Thanksgiving Day was near. The first grade teacher gave her class some fun homework---to draw a picture of something for which they were thankful.

Most of the class drew a turkey or other traditional things. But Douglas drew a different kind of picture. He drew a hand. Just an empty hand.

Douglas was a different boy. He was poor and unhappy. As other children played, Douglas was likely to stand close by the teacher's side.

His classmates were surprised at his picture. One child guessed it was the hand of a farmer, because farmers raise turkeys. Others guessed it was the hand of God, for God feeds us.

The teacher asked him whose hand it was. The little boy said in a low voice,"It's yours."

She remembered the times she had taken his hand and walked with him here and there, as she had the other students. How often she said, "Take my hand, Douglas, we'll go outside. "Or, "Let me show you how to hold your pencil. "Or, "Let's do this together. "Douglas was the most thankful for his teacher's hand.

Tears came into the teacher's eyes.

1.Douglas drew a hand of ______.

A. a farmer B. God C. the teacher D. his own

2.When other children played,Douglas ______.

A. played with other children B. stood quietly by the teacher's side

C. sat in the classroom quietly D. stood by them and watched them play

3.When the teacher knew the truth,she felt ______.

A. surprised B. sad C. moved D. happy

4.Douglas drew the picture of a hand because ______.

A. the teacher asked the students to draw a hand of the teacher

B. most of the class drew traditional things used for celebrating Thanksgiving Day

C. Douglas only liked drawing the hand

D. Douglas was the most thankful for his teacher's hand.

The immune system is the body’s defender. It identifies, tracks down, and destroys troublemakers before they can hurt the body. Those troublemakers may be, for example, bacteria from a cut or splinter, a measles germ, a cold bug, or even a cancer cell. These invaders try to take over our tissues and feed off our bodies’ nutrients. If they succeed, we become sick or, sometimes, even die. It’s the job of our immune systems to destroy these invaders before they destroy us.

Say you picked up a flu virus last week. Perhaps it entered your body through a cut from a drinking glass, or from the air you breathe. Of course, you didn’t feel it, but the virus made its way into your bloodstream. As soon as it entered your body, it began to reproduce. Viruses have only one goal: to take over your cells. Once inside your body, viruses try to enter cells and disrupt their normal work. If left alone, these viruses would hurt so many cells that you would weaken, or worse, get a serious illness.

But this flu virus should not be so complacent as it seems to be. As it reproduces in your bloodstream, the virus is met by a certain kind of white blood cell, the lymphocytes. The lymphocytes are the foot soldiers that keep you alive.

The number of lymphocytes in your body is hard to imagine. Thousands of them could fit in the period at the end of this sentence. Your body holds about a trillion —that’s 1,000,000,000,000 of them, or about 3,000 in every drop of blood. Since you began reading this sentence, over 800,000 of them have been created and destroyed.

Some of these lymphocytes pass through a small walnut-sized organ called the thymus. The thymus is the base of the neck. Here, special hormones turn lymphocytes into fighting cells, called T cells. T cells have one terrific talent: They can tell the difference between friend and foe; what should be in our bodies and what shouldn’t. They do not affect the body ’s healthy cells. Yet they attack everything that is foreign to our bodies, such as germs, transplants, and even our own cells which have become abnormal, as in the case of cancer.

1.What is the function of our immune system?

A. To take over our tissues and feed off our bodies’ nutrients.

B. To prevent bacteria or germs from entering the body.

C. To destroy the troublemakers in order that they might not hurt the body.

D. To fight against T cells.

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

A. Food soldiers. B. Flu virus.

C. White blood cells. D. Troublemakers.

3.The last sentence in paragraph 4 “since you began reading this sentence, over 800,000 of them have been created and destroyed” implies that ____.

A. this sentence contributes to the increase of the number of lymphocytes in your body

B. you would not realize that lymphocytes reproduce themselves rapidly but for th is sentence

C. because you read this sentence, a large number of lymphocytes have been consume d

D. the number of lymphocytes in your body is extremely large

4.Which of the following questions best summaries the main idea of the whole passage?

A. How does the immune system attack the flu virus?

B. How does the immune system function in our body?

C. How do the lymphocytes work in our body?

D. What is the so-called immune system?

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网