What makes it rain? Rain falls from clouds fo...

What makes it rain? Rain falls from clouds for the same reason anything falls to Earth. The Earth's gravity pulls it. But every cloud is made of water droplets or ice crystal(冰晶). Why doesn't rain or snow fall constantly from all clouds? The droplets or ice crystals in clouds are extremely small. The effect of gravity on them is slight. Air currents move and lift droplets so that the net downward amount of water is zero, even though the droplets are moving constantly.

It can be seen that droplets and ice crystals behave somewhat like dust in the air in a beam of sunlight. To the casual observer, dust seems to act in a totally random fashion, moving about

without fixed direction. But in fact dust particles（分子） are much larger than water droplets and they finally fall. The average size of a cloud droplet is only 0.0004 inch in diameter（直径）. It is so small that it would take sixteen hours to fall half a mile in perfectly still air, and it doesn't fall out of moving air at all. Only when the droplet grows to a diameter of 0.008 inch or larger can it fall from the cloud. The average raindrop contains a million times as much water as a tiny cloud droplet. The growth of a cloud droplet to a size larger enough to fall out is the cause of rain and other forms of precipitation. This important growth process is called "coalescence".

1. Ice crystals do NOT immediately fall to Earth because ________.

A. they are kept up by air currents

B. most of them change into steam

C. they combine with other chemicals in the atmosphere

D. their electrical charges draw them away from the earth

2. The underlined word "random" in line 10 most probably means ________.

A. unpredictable    B. strict   C. independent    D. abnormal

3. What can be inferred about drops of water larger than 0.008 inch in diameter?

A. They never occur.

B. They are not affected by the force of gravity.

C. In moving air they would fall to earth.

D.In still air they fall a speed of thirty-two miles per hour.

4. How much bigger is the rain drop than a loud droplet?

A. 200 times bigger

B. 1,000 times bigger

C. 100,000 times bigger

D. 1,000,000 times bigger

高三英语阅读理解中等难度题查看答案及解析

As rain begins to fall from the clouds, it is very pure. However, as it falls through the air it dissolves some of the gases in the air ,It also collects bits of dust and microbes(微生物)that are floating in the air, When the rain reaches the ground it begins to pick up more dust and dirt, Many kinds of mineral substances dissolve in the water ,Sand and nud cannot dissolve in water.

Since water is so important to us, it is very important that the water we use should be clean , Otherwise, we might get some of the diseases that are carried by water Many microbes are harmful ,They are so small that we cannot see them ,These microbes must be removed or killed before the water is not clean, people who drink this water may get these diseases, Thus , to provide people with clean water, the government purifies the water.

Purification is a long process and consists of three stages: storing ,purifying and distributing ,The first stage is storing , Man-made lakes called reservoirs are used for this purpose ,Water from the rains ,other lakes, streams and rivers is collected in the reservoirs ,This water is usually dirty and muddy.

In the second stage shich is purifying , water from the reservoirs is filtered in a special pond, Stones, sand and other unwanted tiny things are caught in it, After that, tiny microbes are still present in the water ,These microbes are removed by “airing ”the water and by adding a chemical substance called chloring(氯)to the water ,This kills all the microbes in the water ,A fter this the water can be safely used for drinking.

The third stage is the distribution of the purified water to homes ,hospitals, offices ,factories and other places, This is done through a network of pipes of various sizes, These pipes must be make of a suitable material.

1.From Paragraph 1, we can learn that ________

A、Rain has contained gases when it forms in the clouds

B、Dust and microbes are dissolved in rain when rain falls on the ground

C、The closer rain is to the ground, the more impure things it contains

D、Sand and mud are things rain collects when it falls through the air

2.According to Paragraph 2 ,the following statements are wrong except that ________

A、All the microbes in water are harmful so water must be purified

B、some diseases can spread through drinking water if it is not clean

C、Water is safe to drink if only harmful microbes are removed from it

D、it is the govrnment’s responsibility to make drinking water clean

3.What can we know about man-made lakes?

A、It is used through the whole process of purification

B、Only rain water can be collected and stored in it

C、Water collected can be stored and filtered in it

D、Water from them contains a lot of impure substances

4.What is the function of the chemical substance chlorine?

A、to air the water            B、to catch tiny things

C、to kill microbes             D、to remove harmful gases

5.What is probably this passage?

A、A news report     B、A book review     C、A magazine article       D、A school paper

高三英语阅读理解中等难度题查看答案及解析

Clouds are gathering, I think we’d better ______for the hotel in case it ______to rain.

A. to head; starts    B. head; starts       C. heading; start     D. heads; start

高三英语单项填空困难题查看答案及解析

Max could smell the rain coming．And it did．Suddenly the lightning flashed through the clouds, nearly ______ him.

A．to blind　 　　　　　　　　 B．blinded　　

C. blinding　 　　　　　　　　 D．having blinded

高三英语单项填空中等难度题查看答案及解析

Max could smell the rain coming．And it did．Suddenly the lightning flashed through the clouds, nearly ______ him.

A．to blind  B．blinded  C. blinding  D．having blinded

高三英语单项填空中等难度题查看答案及解析

Max could smell the rain coming. And it did. Suddenly the lightning flashed through the clouds, nearly__________him.

高三英语单项填空简单题查看答案及解析

______the heavy rain, we ______the town.

高三英语单项填空简单题查看答案及解析

Rain and cold weather this summer saw honey yields from hives(巢)fall by almost three-quarters, the British Beekeepers Association(BBKA)said today. The average crop per hive was down 72% compared to last year, with just 3.6kg (81b) of honey produced compared to an annual average, the annual honey survey by the BBKA revealed.

The survey of 2,712 beekeepers in England, Northern Ireland and Wales found that 88% said this summer’s bad weather caused the descent in honey yields. The bad weather made it difficult for bees to excrete(排泄),which led to disease easily, and the bad weather also increased the risk of keeping bees for heavy rain caused the places which bees regularly visited to meet natural disasters. The bad weather also influenced the plants flowering which increased the cost of keeping bees. The BBKA issued a midsummer warning to feed bees if necessary to avoid dying from hunger. But in London, which recorded the worst results with just 2.5kg (5.61b)of honey harvested on average, beekeeping experts said that in addition to the bad weather there was a lack of food for bees in the city.

Angela Woods, secretary of the London Beekeepers Association, said, “Rather than putting beehives on office roofs, we encourage companies in London that want to help to look at different ways of supporting bees and beekeepers. We need more food for the bees and better-educated beekeepers.”

Elsewhere, the weather was the main problem. Peter Hutton, a beekeeper in Tunbridge Wells, Kent, said, “It has been the most difficult year I have known in my 53 years of beekeeping. Bad weather in spring prevented bees in many areas from collecting nectar(花蜜)from early-flowering crops such as oilseed rape(油菜),and the rain continued in many places throughout June and July, preventing honeybees from searching for food on later crops.”

The BBKA warned that as well as reducing the honey harvest, the bad weather is likely to have a longer-term influence as it will have affected the normal process of breeding for the queens, which mate(交配)on the wing on fine, still summer days. As a result they may have mated poorly and be unable to produce enough new babies to see groups through the winter.

1.According to the passage, last year the average crop per hive might be____.

A.5 kg

B.7.2 kg

C.10kg

D.13 kg

2.The underlined word “descent” means_____.

A. fall　　　　　　　 B. rise

C. disease　　　　　 D. variety

3.What caused the lack of food?

A. The bad weather in both autumn and winter.

B. The bad weather in both winter and spring.

C. The bad weather in both spring and summer.

D. The bad weather in both summer and autumn.

4.What does the last paragraph mainly tell us?

A. The bad weather just affects honey harvest.

B. The bad weather has effect on bees’ breeding.

C. The bad weather only has a short-term impact on bees.

D. The bad weather has effect on bees’ life in winter.

5. Which of the following statements is NOT true according to the passage?

A. The quality of the honeybees is influenced by the bad weather.

B. London companies are encouraged to take part in helping bees and beekeepers.

C. Both the cost and the risk of keeping bees are increased because of the bad weather.

D. Better-educated beekeepers are needed to improve the bad situations that the bad weather brought to bees.

高三英语阅读理解中等难度题查看答案及解析

—Can we go camping tomorrow，as planned？

—I’m afraid not. The dark clouds ________ a heavy rain.

高三英语单项填空中等难度题查看答案及解析

— I hear it will rain tomorrow.

— It _______ true. You see, there are so many black clouds in the sky now.

高三英语单项填空困难题查看答案及解析