Stars ___________ their own light, while plan...

Stars ___________ their own light, while planets only ___________ the light.

A.give off; reflect B.give away; reflect C.reflect; give off D.reflect; give away

高二英语单项填空中等难度题查看答案及解析

Scientists have found a potentially habitable(可居住的)planet and its star outside our Solar System are more similar to the Earth and our Sun than any other known planet-star pair. For now, the planet candidate(候选)is known as KOI-456.04. If its existence is confirmed by other telescopes, the planet would join a group of about 4,000 known planets outside our Solar System.

“It's the combination of its size less — than — double that of the Earth and its solar-type host star that makes it so special and familiar” Ren6 Heller, the lead author of the new study, said in a press release. That means it could potentially host life.

To be considered habitable, planets must orbit a stable star that keeps a temperature suitable for liquid water. The vast majority of identified Earth-like planets don't meet the conditions required for life to exist. They give off either too weak light or high-energy flames that can fry the planets around them. The star that KOI-456.04 orbits is about 1.1 times the size of the Sun, with a surface temperature of only 300 degrees Celsius less than the Sun. The star also sends out visible light, like our Sun does. Plus, KOI-456.04 is less — than — double the size of the Earth, which could mean its atmospheric conditions are similar to ours. If KOI-456.04 s atmosphere is like the Earths — meaning it has a mild greenhouse effect, then its average surface temperature would be about 5 degrees Celsius, compared to the Earth's average of 15 degrees Celsius, according to the Max Planck Institute .

The system is just over 3,000 light-years away from our Solar System. Future space telescopes could study the planet candidate further. NASA, the European Space Agency, and the Canadian Space Agency plan to launch(发射)the James Webb space telescope in 2021. The European Space Agency's PLATO space telescope, scheduled to launch in 2026, will focus on finding Earth-like planets orbiting Sun-like stars.

1.What makes the newly-found planet special?

A.Its strange name. B.Its extremely large size.

C.Its potential to host life. D.Its relationship with the Sun.

2.What does the underlined word “orbit” mean in paragraph 3?

A.Move around. B.Stick to.

C.Knock into. D.Depend on.

3.Which of the following do the scientists care while studying KOI-456.04?

A.What kind of energy its host star provides.

B.Whether its atmosphere is similar to the Earth's.

C.How many agencies are willing to join in the study.

D.Why its surface temperature is lower than the Earth's.

高二英语阅读选择中等难度题查看答案及解析

Is there anybody out there? For centuries human beings have been wondering. As we've gained greater understanding of the universe, however, our searches have taken on a more concrete form. Questions about aliens have become a subject for science rather than science fiction and philosophy.

Now a new cooperation(合作)between the Very Large Array observatory in New Mexico and the privately funded Seti Institute in California could mean that our curiosity about aliens is closer than ever before to being satisfied. Data from the VLA's 28 giant radio telescopes will be fed through a special supercomputer that will search for distant signals. Scientists who work at the Seti Institute said the announcement means their research is now “almost mainstream".

How likely it is that a signal will be found, and what this might mean, are hard questions to answer. Seti's existing projects haven't detected any life signals from other planets so far. But recent discoveries in space and Earth sciences have provided some encouragement to those who are enthusiastic about the likelihood, however remote, of detecting other civilizations.

While once it was thought that our solar system could be unique, since the discovery of the first exoplanet (a planet in another solar system) in the 1990s, thousands more have been located(确定位置). Around one in five stars are now thought to have a planet in their orbit in a so-called “habitable zone"—that is at a distance from the star where the temperature(neither too hot nor too cold) means that life is theoretically feasible.

If there is another life form somewhere, could it be as intelligent as us? Or cause a risk to us, as the physicist Stephen Hawking once warned? As investigations of Mars continue, our interest in the possibility of alien life appears clear—especially when conditions in our own earth appear even more unstable.

1.What can we learn from the first two paragraphs?

A.Global cooperation helps to study aliens.

B.Searching for aliens is becoming a trend.

C.Aliens have caught wide attention globally.

D.There are many uncertainties about aliens study.

2.What is the encouraging news to searchers for distant civilizations?

A.VLA has developed new radio telescopes.

B.Seti has detected signals from other planets.

C.More and more exoplanets have been found.

D.Other civilizations have been located in a habitable zone.

3.What does the underlined word “feasible" in paragraph 4 most probably mean?

A.Possible. B.Tough.

C.Easy. D.Certain.

4.In which section of a newspaper may this text appear?

A.Literature. B.Health.

C.Education. D.Science.

高二英语阅读选择中等难度题查看答案及解析

In the film The Matrix, Agent Smith, a super-computer in human shape, says, “You move to an area, and you multiply, and multiply, until every natural resource is consumed. The only way you can survive is to spread to another area. There is another organism on this planet that follows the same pattern: a virus. Human beings are a disease, a cancer of this planet. ”

Yes, relatively speaking, we are just a large virus. While most species live in balance with their ecosystems, we fail to do so. We are taking more from nature than it has to give. We wipe out animals and plants as a virus might invade and kill a host. We are destroying our host, the earth.

Our brain has been our most successful tool for survival. The funny thing is that our mind has developed to such a degree that we have thought up solutions to more survival problems. We are for the first time in earth's history changing nature to suit our comfort and desires. Being a human, I do like the advancement of technology and medicine as we nave the chance to survive longer and sometimes feel less pain. After all, nature is cruel and we can soften its blow through these inventions. However, people surviving genetic faults or illness, could they be actually making the gene pool more “dirty” and could even more people in the future suffer due to an increase in faulty DNA? It seems that even though we deal with a short-term problem we could be causing more. Are we being kind to be cruel?

We are lucky enough to own a brain complex enough to think and create. But we fail to realize the only way to really survive is through respect of our host, the earth, and working with it as the only way a living thing can benefit is by benefiting its host as it depends on it to survive.

1.According to the passage, what characteristics do humans and viruses share?

A.They take and give. B.They expand and destroy.

C.They create and consume. D.They balance and survive.

2.What does the author think of modern technology and medicine?

A.They can help humans control nature. B.They can guarantee purer human DNA.

C.They may reduce humans' effect on the earth. D.They may bring humans more harm than good.

3.What is the author's purpose of writing the passage?

A.To appeal for humans' respect for nature. B.To put forward ways to advance medicine.

C.To talk about a film character, Agent Smith. D.To argue against comparing humans to viruses.

高二英语阅读选择中等难度题查看答案及解析

Astronomers （天文学家） say they are on the point of finding planets like Earth orbiting other stars, which is a key step in determining if we are alone in the universe．

A top NASA official and other leading scientists say that within four or five years they should discover the first Earth-like planet where life could develop, or may have already．A planet close to the size of Earth could even be found sometime this year．

At the annual American Astronomical Society conference this week, each discovery involving  so-called “exoplanets” —those outside our solar system — pointed to the same conclusion：Quiet planets like Earth where life could develop probably are plentiful．

NASA’s Dew Kepler telescope and a lot of new research from the suddenly hot and competitive exoplanet field caused noticeable buzz at the meeting．Scientists are talking about being at “an incredible special place in history” and closer to answering the question．“Are we alone? For the first time, there’s an optimism that sometime in our lifetimes we’re going to get to the bottom of that,” said Simon Worden，an astronomer who heads NASA’s Ames Research Center．“If I were a betting man, which I am, I would bet we’re not alone．”

“These are big questions that reflect upon the meaning of the human race in the universe,” the director of the Vatican Observatory, the Rev．Jose Funes, said Wednesday in an interview at this week’s conference．

Worden told The Associated Press: “I would certainly expect in the next four or five years we’d have an Earth-sized planet in the habitable （可居住的） zone．”

1.What is very important in determining if we are alone in the universe?

A．Finding an Earth-like planet．             B．Orbiting other stars．

C．Developing new telescopes．                D．Finding more exoplanets．

2.What’s an exoplanet?

A．It’s a planet like Earth．                     B．It’s a planet outside our solar system．

C．It’s a planet orbiting the sun．              D．It’s a planet where life have developed．

3.The underlined phrase “get to the bottom of” probably means “__________”．

A．understand fully

B．make full use of

C．search for

D．do more research on

4.From the passage we can learn that __________．

A．an Earth-like planet has been found

B．it’s been proved we are not alone in the universe

C．Jose Funes has found the meaning of the human race in the universe

D．the discovery of an Earth-like planet could happen in the near future

高二英语阅读理解中等难度题查看答案及解析

Trees are commonly cut down for wood and paper. 1.. The unique chemical process that trees and plants use to turn light energy from the sun into oxygen is known as photosynthesis (光合作用).

2.

The production of oxygen is a result of photosynthesis, but it is not the main purpose of this process. 3.. Plants create their own food through photosynthesis. During this process, a plant’s roots absorb water from the ground, and its leaves take in light energy and carbon dioxide. The plant uses these elements to make fats and proteins that are then used to maintain the plant’s life.

The process of photosynthesis

The first step in photosynthesis is using the sun’s energy. During this process, chlorophyll (叶绿素) absorbs the light energy of the sun. The energy from the sun then acts upon the water absorbed by the roots of the plant. Carbon dioxide sent into the atmosphere by animals and humans is then absorbed by the plant’s leaves and paired with the hydrogen to produce sugar. The sugar is turned into plant food. 4..

Threats to tree photosynthesis

5.. Today, only about 30 percent of Earth’s land is covered in trees. This is contributing to global warming since trees are necessary to consume the carbon dioxide in the atmosphere. Experts believe planting trees is vital in order to ensure the preservation of the delicate balance that enables photosynthesis.

A.The purposes of photosynthesis

B.The advantages of photosynthesis

C.In fact, oxygen is simply a by product

D.It is also responsible for giving plants their green color

E.During this process, extra oxygen is produced and released

F.The trees that change carbon dioxide into oxygen are disappearing rapidly

G.But the greatest value of trees comes from their ability to turn the sun’s energy into chemical energy

高二英语七选五中等难度题查看答案及解析

On a clear night, you can see a sky paced with stars. But you can’t see planets orbiting any of these stars, even with the strongest Earth—based telescopes. Astronomers reported that they discovered seven Earth—sized planets orbiting a nearby star called TRAPPIST – 1 in February. They had to rely on indirect evidence to tell them that the planets are there. By doing some math, they figured out the number of planets and the distance of their orbits.

TRAPPIST – 1 is a red dwarf （红矮星）, much smaller than our sun, but larger than Jupiter (木星). If the sun were the size of a basketball, TRAPPIST – 1would be the size of a gold ball. This star is one of our closest neighbors, just like the moon to the earth in space.

When astronomers using Earth-based telescopes to study TRAPPIST – 1,they noticed that every once in a while, it became slightly dim（昏暗）. They decided that a planet must be passing in front of the star, blocking part of the light. This dimming would come and go as the planet orbited the star, passing alternately (交替地) behind and in front of the star regularly.

By making careful observations, astronomers expected to get a rough idea of the planet’s size from the pattern of dimming light. But the light level changed often and not at evenly spaced (均匀间隔的) times. The astronomers had to conclude they were looking at more than one planet! To get additional data, NASA’s spritzer Space Telescope measured TRAPPIST –1’s brightness nearly continuously for 20 days, catching 34 crossings of planets in front of the star. Sorting through the mess of data, the astronomers found that the innermost planet completes its orbit in 1.5 Earth days, while the outermost planet takes 20 days. Once you know how long it takes each planet to complete an orbit, you can work out how far it is from the star compared with the other planets.

The TRAPPIST – 1 planets are not alone. So far, astronomers have found more than 3,400 planets that orbit other stars.

1.How did astronomers know the number of planets orbiting TRAPPIST –1?

A. They used their eyes.　　 B. They used telescopes.

C. They performed some calculation.　　 D. They made some guess.

2.How does the author introduce TRAPPIST – 1 in paragraph 2?

A. By giving examples.　　 B. By making comparisons.

C. By providing research results.　　 D. By listing some numbers.

3.What probably causes the star TRAPPIST – 1 to be slightly dim?

A. The telescope’s failure.　　 B. The cloud floating around.

C. The star’s moving.　　 D. The passing planets.

4.What’s the main idea of Paragraph 4?

A. The ways to get the information of the planets.

B. The introduction of the planets.

C. The distances of the planets to the star.

D. The astronomers’ effort of exploring TRAPPIST – 1.

高二英语阅读理解中等难度题查看答案及解析

Do you know what a big dream is?1.Or, is a big dream something that provides only entertainment? Children dream big dreams, but there are three barriers to realizing dreams. They often kill them before they ever have a chance to grow.The SelfImmediately following the birth of a big dream, a negative self-talk takes over and gives all the reasons why it cannot happen. This inside voice is the ego（自我）. It’s there for protecting and should be listened to.2.Most people are influenced by the inside voice. That’s why only a handful of people make their dream come true.3.Family and friends are a lot like the ego. They want to protect those they love, so they will often list all the reasons why the big dreams won’t come true. Sometimes, family and friend destroy dreams of those they love most, out of their own fear of being left behind.The WorldIf one gets past the first two barriers, one has to face the world.4.In the past, big dreamers were locked up and sometimes even killed when they were shown to the world. Fortunately, in most of the world today, big dreamers just get laughed at.The way to realize a big dream is with confidence and action. When children have confidence and then take action, they will be ready to accept any failure. The truth is that every great dreamer whose dreams have never seen the light of success knows failure well.5.

A.Does a big dream show one’s future ?

B.They simply fail until they succeed.

C.How Big Dreams Die

D.It is the last and the most terrible barrier.

E.Family and Friends

F.Sometimes it is right, but more often it is wrong

G.And their big dream is to be a rock star or a famous artist.

高二英语七选五中等难度题查看答案及解析

Each year, thousands of U.S. families open their homes and hearts to visitors from all over the world. In a homestay, students can observe, learn and experience a new lifestyle and culture, while practicing English skills in a home environment. Successful homestay experiences can help to ease homesickness for international students.1.

What makes homestays special is the daily experience of living with hosts who arc eager to share their way of life. Homestay hosts will reflect the diversity of the region in which they live. They may be single parents, retired couples or young families.2.What they will have in common is a desire to share their homes and their time with international students.

3.Most homestay hosts will give the student a list of simple house rules to help everyone live happily together. They may give guidelines about Internet usage, lawn勿(洗衣房), television viewing, meal times, keeping the bedroom and bathroom clean, and money matters.4.For example, at the University of Delaware, all homestay hosts living more than one mile from campus(校园)must provide transportation to and from campus every day of the week. Hosts must also provide each student with a private, furnished room which has a desk, a bed, a closet and enough lighting. Students will have access to a shared or private bathroom as well.

There is no better way to gain special insight into U.S. culture, while improving English language skills, than by participating in a homestay. It's not only important to get high scores in English testing, but to also learn how to get along with people from all over the world.5.

Occasionally, problems arise that cannot be solved. In these cases, the student can ask for another homestay or explore other housing options. The homestay coordinator(协调员)will work closely with the student to ensure that the next homestay will be a good match.

A.Unfortunately, not all homestay matches are perfect.

B.Living in a homestay will always require an adjustment period.

C.They will come from different socioeconomic and ethnic backgrounds.

D.Homestay hosts are expected to provide an English-only speaking environment.

E.Homestays provide students with a well-rounded education and great social skills.

F.Also, they can help students smoothly adapt to the life of an American university.

G.For universities offering homestays, it's important to set standards for licensed hosts.

高二英语七选五中等难度题查看答案及解析

Most of the flowers in nature are red, orange and yellow. If we have seen a black flower, it’s a chance in million. People have made a census (普查) to colors of more than four thousand kinds of flowers and discovered that only eight of them are black. As we know, sunlight is formed by seven different colored lights. The wave length of each light is different, so the quantity of heat in each light is also different. Flowers, especially their petals (花瓣), are easy to be harmed by high temperature. Black flowers can take in all the light waves which cause the flowers to dry up in a high temperature. So black flowers can rarely survive sunlight. But red flowers, orange flowers and yellow flowers can protect themselves from sunlight by reflecting the red light, orange light and yellow light, each of which has a large quantity of heat.

1.It is _________ to see a black flower.

A.impossible B.seldom

C.common D.no chance

2.The passage tells us that ________________.

A.black flowers are so weak that it is difficult for them to grow up.

B.there is only eight black flowers in nature.

C.sunlight is formed by seven different colored lights, so the wave length of each light is different.

D.black flowers can take in the light of all the wave lengths which make them dry up because of high temperature.

3.Which of the following ideas is NOT true?

A.People have found that only a few kinds of flowers are black.

B.Flowers are easy to be harmed by very high temperature.

C.Red, orange and yellow flowers can also absorb the light of all wave lengths.

D.The black flowers cannot protect themselves from sunlight.

高二英语阅读选择中等难度题查看答案及解析