Some ________ chemicals and food additives （添加剂) are known to increase cancer risk.

食品添加剂(food additives)

If you know how many carbohydrates, fats and proteins are in any given food, you know

A．how much energy that food contains

B．the compilation of these three building blocks

C．how the energy is acquired

D．where does the food come from

Plants and Diseases

1 Plants, like animals, are subject to diseases of various kinds. It has been estimated that some 30,000 different diseases attack our economic plants; forty are known to attack corn, and about as many attack wheat. The results of unchecked plant diseases are all to obvious in countries which have marginal food supplies. The problem will soon be more widespread as the population of the world increases at its frightening rate. Even in countries which are now amply fed by their agricultural products there could soon be critical food shortages. It is easy to imagine the consequences of some disastrous attack on one of the major crops; the resulting famines could kill millions of people, and the resulting hardship on other millions could cause political unrest disastrous to the order of the world.

2 Some plants have relative immunity to a great many diseases, while others have a suceptibility(易感性) to them. The tolerance of a particular plant changes as the growing conditions change. A blight(枯萎病) may be but a local infection easily controlled; on the other hand it can attack particular plants in a whole region or nation. An example is the blight which killed virtually every chestnut tree in North America. Another is the famous potato blight in Ireland in the last century. As a result of that, it was estimated that one million people died of starvation and related diseases.

3 Plant scientists have made remarkable strides in identifying the pathogens(病原菌) of various diseases. Bacteria may invade a plant through an infestation(大批出没)of insect parasites carrying the pathogen. Other diseases might be caused by fungus(真菌)which attacks the plant in the form. of rust.

4 Frequently such a primary infection will weaken the plant so that a secondary infection may result from its lack of tolerance. The symptoms shown may cause an error in diagnosis, so that treatment may be directed toward bacteria which could be the result of a susceptibility caused by a primary virus infection.

A Improvement in Researching Diseases

B The Results of Plant Diseases

C Mistake made in Diagnosis

D Killing Insects

E A Major Crop Disease

F The Reasons of Plant Diseases

Paragraph 2 ______

听力原文：W: This food is terrible! I can't even finish my dinner.

M: I know, you think with all the money we paid for room and board, the university could hire a better food service. Where are you heading next?

W: I'm going over to the student recreation center to play some bridge.

M: You are spending your time on a card game?

W: Not just a card game. It's one of the most strategic games.

M: So I have heard. Don't you play with a partner?

W: Yeah! Four people play, two against the other two.

M: So, you try to play in cooperation with your partner?

W: Actually, the cards of one of the four players are turned face-up. That player is called the dummy.

M: I wouldn't want to be called that. When you are the dummy, what do you do while the cards are being played?

W: Anything you want. Sit there and study, shuffle another deck, get snacks for everyone... I like to stand behind my partner and watch. That is very interesting.

M: You know, I've heard that bridge is habit-forming. You should be careful not to play so much that you don't get your studying done.

W: Don't worry about me. I only play cards on Thursday after dinner, and sometimes when they need a fourth player. If you like, I could teach you.

M: Thanks, but I have a pretty heavy workload this semester. I already spend my evenings doing things I don't really know how to do yet.

W: I know you are busy, but sometimes you need to have a rest.

19．How does the woman plan to spend her evening?

20.What will the woman probably do if she is the dummy?

21.What does the man warn the woman not to do?

22.Why doesn't the man accept the woman's offer?

(23)

A．Playing cards.

B．Preparing snacks.

C．Studying with a partner.

D．Learning how to design bridges.

听力原文：W: This food is terrible. I can't even finish my dinner.

M: I know. You think with all the money we pay for room and board, the university could hire a better food service. Where are you headed next?

W: I'm going over to the student recreation center to play some bridge.

M: You are spending your time on a card game?

W: Not just any card game. It's one of the most strategic there is.

M: So I’ve heard. Don't you play with a partner?

W: Yeah. Four people play, two against the other two.

M: SO you try to play in cooperation with your partner.

W: Actually, the cards of one of the four players are turned face up. That player is called the dummy.

M: I wouldn't Want to be called that. When you are the dummy what do you do while the cards are being played?

W: Anything you want. Sit there and study, shuffle another deck, get snacks for everyone. I like to stand behind my partner and watch.

M: You know. I've heard that bridge is habit forming. You should be careful not to play so much that you don't get your studying done.

W: Don't worry about me. I only play Thursdays after dinner, and sometimes when they need a fourth player. If you like, I could teach you.

M: Thanks. But I have a pretty heavy workload this semester. I have to spend my evenings studying. I don't really know how to do it yet.

(23)

A．In the student recreation center.

B．In the university bookstore.

C．In the campus dining hall.

D．In a classroom.

听力原文：W: This food is terrible! I can't even finish my dinner.

M: I know. You think with all the money we paid for room and board, the university could hire a better food service. Where are you headed next?

W: I'm going over to the student recreation center to play some bridge.

M: You are spending your time on a card game?

W: Not just any card game. It's one of the most strategic ones.

M: So I have heard. Don't you play with a partner?

W: Yeah! Four people play, two against the other two.

M: So, you try to play in cooperation with your partner?

W: Actually, the cards of one of the four players are turned face up. That player is called the dummy.

M: I wouldn't want to be called that. When you are the dummy, what do you do while the cards are being played?

W: Anything you want. Sit there and study, shuffle another deck, get snacks for everyone I like to stand behind my partner and watch.

M: You know, I've heard that bridge is habit forming. You should be careful not to play so much that you don't get your studying done.

W: Don't worry about me. I only play Thursdays after dinner, and sometimes when they need a forth player. If you tike, I could teach you.

M: Thanks, but I have a pretty heavy workload this semester; I already spend my evenings doing things I don't really know how to do yet.

(23)

A．In the student recreation center.

B．In the campus dining hall.

C．In the university bookstore.

D．In a classroom.

听力原文：W: This food is terrible! I can't even finish my dinner.

M: I know. You think with all the money we paid for room and board, the university could hire a better food service? Where are you headed next?

W: I'm going over to the student recreation center to play some bridge.

M: You are spending your time on a card game?

W: Not just any card game. It's one of the most strategic there is.

M: So I have heard. Don't you play with a partner?

W: Yeah! Four people play, two against the other two.

M: So, you try to play in cooperation with your partner.

W: Actually, the cards of one of the four players are turned face up. That player is called the dummy.

M: I wouldn't want to be called that. When you are the dummy, what do you do while the cards are being played?

W: Anything you want. Sit there and study, shuffle another deck, get snacks for everyone ... I like to stand behind my partner and watch.

M: You know, I've heard that bridge is habit-forming. You should be careful not to play so much that you don't get your studying done.

W: Don't worry about me. I only play Thursdays after dinner, and sometimes when they need a forth player. If you like, I could teach you.

M: Thanks, but I have a pretty heavy workload this semester. I already spend my evenings doing things I don't really know how to do yet.

How does the woman plan to spend her evening?

A．Studying.

B．Playing bridge.

C．Playing ball games.

D．Watching games.