B. Students don't sleep well because of alerting systems.

C. One's body clock governs the sleep/wake cycle independently.

D. Adolescents' delayed sleep/wake cycle isn't the preferred pattern.

3. Which of the following is closest in meaning to the underlined word "classified"?

A. Criticised. B. Grouped. C. Organised. D. Named.

4. What does the text mainly talk about?

A. Functions of the body clock.

B. The "night owl" phenomenon.

C. Human beings' sleep behaviour.

D. The school schedule of "early birds".

答案

1. C　2. D　3. B　4. B　

　　This year arrives amid a few interesting trends. More Americans are interested in local and sustainable food: urban farming, chicken-raising. And more Americans are hunting, spending increasing time and money on that pursuit.

　　Viewed from the right angle, though, both these trends could have a place at the holiday table. What would happen if more Americans made Thursday's (Thanksgiving Day) meal out of wild turkeys? What if more people enjoyed a wild Christmas goose, or wild pig ham? If more did, the result might be better for the environment, for our health-and perhaps for our souls as well.

Americans' growing interest in local food is evident everywhere. According to the US Department of Agriculture, the number of farmers' markets rises from 1, 755 in 1994 to 8, 144 this year. Cities from Ann Arbor, Michigan, to Gainesville' Florida, have eased restrictions on backyard chickens. Some "locavores" are content to get community-supported agricultural produce delivered, and buy grass-fed beef. But for a growing number, hunting is the next step. The meat is local and avoids the ethical complications of factory farms.