He talked about a hero ____ no one had ever h...

He talked about a hero ____ no one had ever heard.

高三英语单项填空简单题查看答案及解析

Have you ever heard a news reporter talk about DNA? Reporters talk about DNA found at the scene of a crime. They talk about police finding DNA “fingerprints.” Police sometimes use DNA as a clue to find out who committed the crime.

DNA is a substance（物质） that makes up genes. Everything alive has genes. Plans have genes. Animals have genes. You have genes.

Genes are the basic units of heredity（遗传）. Heredity means all the characteristics you inherit from your parents. You get your genes from your parents. You inherit half of your genes from your mother. You inherit half of your genes from your father.

Genes are a kind of code. A tree’s genes tell what shape its leaves will be. A cat’s genes tell what color its fur will be. Your genes tell what color your eyes will be. Your genes tell what color your hair will be. Everything about you comes from the code in your genes.

Genes line up on strands（链） called chromosomes（染色体） in cells. Everything alive is made up of cells. Chromosomes are in the center, or nucleus, of cells.

Different parts of you are made of different kinds of cells. Your muscles are made of muscle celIs. Your skin is made of skin cells. The code in your genes tells your body to make different kinds of cells. The genes in each cell tell the cell how to work. They tell the cell when to make new copies of itself.

An Austrian monk named Gregor Mendel first saw inherited patterns in pea plants. He experimented with pea plants in the 1860s. One of the things, or traits（特质）， Mendel studied was what makes some pea plants tall and some short. He said that the traits must come from units of heredity passed from the parent plants. These units were later called genes.

In the mid-1900s, scientists discovered that genes are made of DNA. In the 1970s, scientists learned how to change DNA with genetic engineering. Scientists also learned that problems with certain genes cause diseases. Muscular dystrophy, cystic fibrosis, and hemophilia are some genetic diseases-diseases caused by problems in genes. Today, scientists are looking for ways to cure genetic diseases by changing genes through a process called gene therapy.

1. What is DNA?

A. DNA is a kind of gene.

B.. DNA is a substance that makes up genes.

C. DNA is the basic unit of heredity.

D. DNA is a measure to protect crime.

2. Which of the following about genes is correct according to the passage?

A. Plants, animals and human beings have the same genes.

B. Half people inherit all genes from their mother, others from their father.

C. Genes decide the trees shapes, the cats’ fur color and our eyes’ color as well.

D. Genes will give you a code when you need them.

3.Where are genes?

A. Genes lining up on strands called chromosomes are in the center of cells.

B. Genes hide in everything alive in your body.

C. Genes can be nowhere but in your mind, controlling all your actions.

D. Genes travel in your body and help cope skin, muscle, and eyes.

4.An Austrian monk named Gregor Mendel ________.

A. first saw inherited patterns in people

B. was interested in why plants were different

C. first called the units of heredity from parents genes

D. was the first who discovered genes

5. We can conclude that ________.

A. scientists were less intelligent than monks in 1900s

B. some genes are bad and can cause diseases

C. we don’t need to worry about genetic diseases any longer

D. the discovery of genes may be of great help in our daily life

高三英语阅读理解中等难度题查看答案及解析

_____ the police thought he was the most likely one, since they had no exact proof about it,they had to set him free.

A．As long as         B．If only            C．Although          D．As though

高三英语单项填空中等难度题查看答案及解析

Although the police thought he was the most likely one, _____ they had no exact proof about it, they could not arrest him.

A. when          B. until            C. before           D. since

高三英语单项填空中等难度题查看答案及解析

______ the police thought he was the most likely one, since they had no exact proof about it, they could not arrest him.

高三英语单项填空中等难度题查看答案及解析

______ the police thought he was the most likely one, since they had no exact proof about it, they could not arrest him.

A. Although        B. As long as    C. If only         D. As soon as

高三英语单项填空中等难度题查看答案及解析

________ the police thought he was the most likely one，since they had no exact proof about it，they could not arrest him.

A．Although　 B．As long as

C．If only　 D．As soon as

高三英语单项填空中等难度题查看答案及解析

________ the police thought he was the most likely one，since they had no exact proof about it，they could not arrest him.

A．Although　             B．As long as

C．If only　                 D．As soon as

高三英语单项填空中等难度题查看答案及解析

语法填空

阅读下面材料，在空白处填入适当的内容(不多于3个单词)或括号内单词的正确形式。

One day I heard two girls talking about making net friends in a café. One said that she ___1.___(meet) one of her net friends and the other told her not to because most people found their net friends __2.____ (disappoint) in real life.

We all know it is quite common now that many teenagers, especially ___3._ from one-child families, like to make net friends and spend lots of time ___4._____(chat)with them because they need someone to talk with and share their sorrow and ___5._____(happy). However, is it wise for them to do so?

In my opinion, it is possible ___6.__ you to find some real good friends with the help of new technology but you have to take care. When you talk with someone unknown on the Internet, you have no idea at all what kind of person he is and　　 _7.___ he is telling you the truth. ___8.___, we can’t deny that some bad guys mask themselves very well so that they can get many nice people ___9.__ (trap). So, you’re taking the risk of meeting your net friends before you get any idea about him. In a word, you can never be careful enough when __10.___ (meet) your net friends.

高三英语语法填空简单题查看答案及解析

He told me that he had two girl-friends, neither of _______ knew anything about the other.

高三英语单项填空简单题查看答案及解析