1. A recent experiment showed that ________________.

　 A. different flowers open and close at different times of day

　 B. for their opening and closing, flowers do not need information from the outside world

C. flowers are influenced by weak light even when they are in a dark room

D. flowers can be used for telling the time

5. This passage is a (an) _______________________.

　 A. book　　　 B. report　　　 C. advertisement　　　 D. picture

　 ⑾We have known for a long time that flowers of different plants open and close at different time of day. This is so familiar that there seems to be no need to ask the reason for it. Yet no one really understands why flowers open and close like this at particular times. The process (过程) is not as simple as we might think, as recent experiments have shown. In one study, flowers were kept in constant (连续的) darkness. We might expect that the flowers, without any information about the time of day, did not open as they normally do. In fact, they continued to open at their usual time. This suggests that they have some mysterious (神秘的) way of knowing the time. Their sense of time does not depend on information from the outside world; it is, so to speak, inside them, a kind of “inner clock”.

This discovery (发现) may not seem to be very important. However, it was later found that not just plants but also animals -including man -have this “inner clock” which controls the working of their bodies and influences (影响) their activities. Men, then, are also influenced by this mysterious power. Whether we wish it or not, it affects such things in our life as our need for sleep, our need for food.

In the past, this did not matter very much because people lived in natural condition. In the modern world, things are different; now there are spacemen, airplane pilots and, in ordinary life, a lot of people who have to work at night. It would be very useful, then, to know more about the “inner clock”. Such ordinary things as flowers might help us understand more about ourselves.

4. If you want to rent a color television, ____________________.

　 A. leasing company (租赁公司) can have your set installed the same day

　 B. you can have a choice of sets to rent

　 C. leasing company will install an aerial for you free of charge

　 D. you must have an aerial

3. What does “pay in advance” mean?

A. You pay the rent for a period of time before you actually get the television.　

B. You go ahead and pay the rent.

C. You pay the rent in front of anyone.

D. You will be the first to pay the rent.

2. What is the good of paying twelve months’ fees when you begin to hire?

　 A. One and a half months’ hire free of charge.

　 B. One month’s hire free of charge.

　 C. Half a month’s hire free of charge.

　 D. One-fourth of a month’s hire free of charge.

1. From the passage we know _______________________.

A. the more you rent, the less you pay

B. the lowest weekly rental fee is much more than $12

C. the longer you rent, the less you pay

D. if you rent a TV set for a long time, service and spare parts will be free

6. If you decide that you want to stop renting and buy the set you have on hire, this can be arranged-with a generous allowance (折扣) for the fees already paid.

5. No deposit (押金) is needed. You pay only the monthly rental fee. But if you pay in advance, you can save money. Pay twelve months’ fees when you begin to hire, and we’ll give you a month’s hire without charge.

4. You can choose from all kinds of models, and what’s more, if after a certain period of time, and you would like a new model, you can change. How’s that for service?

3. If you don’t have an aerial (天线), we’ll install one for you, and that will be free, too. All you have to pay is the installation charge (安装费)!