单选题 In recent years, many Americans of both sexes and various ages have become interested in improving their bodies. They have become devoted to physical fitness. The need to exercise has almost become compulsive with many persons who have a strong desire to be more physically fit.
By nature, Americans are enthusiastic and energetic about their hobbies and pastimes. They apply this enthusiasm, and energy to jogging/running. As a result, there are running clubs to join and many books and magazines to read about running.
The desire to be physically fit is explained by a "passion" for good health. The high rate of heart attacks in the 1960s caused an increase on the part of the public in improving the human body.
Middle-aged men especially suffer from heart attacks. Thus, they are one group strongly interested in more physical exercise. In fact, many doctors encourage their patients to become more physically active, especially those who have sedentary jobs. It is interesting to note that the rate of heart attacks began to decrease in the 1970s and it is still decreasing.
Physical fitness currently enjoys a favored role in the United States. It is a new "love" that many Americans have cherished. Will it last long? Only time will tell or until another "new passion" comes along.

单选题 In recent years, many Americans have become interested in improving their bodies because ______.

A. they are enthusiastic about their hobbies and pastimes
B. they have a strong desire to be more physically fit
C. there are many running clubs to join
D. there are many books and magazines to read about running

【正确答案】 B

【答案解析】[解析] 题目要求回答，近年来许多美国人为何热衷于改进体质。第一段最后一句话解释了这一原因。B项为正确答案。

单选题 The passage implies that ______ is a great favorite of many Americans, men and women, old and young.

A. jogging/running
B. joining running clubs
C. reading books and magazines about running
D. going in for all kinds of sports

【正确答案】 A

【答案解析】[解析] 从文中第二段可知，美国人生来就喜欢消遣和有嗜好。他们热衷于慢跑，结果各种慢跑俱乐部和慢跑运动书刊到处都有。

单选题 Middle-aged men suffering from heart attacks ______.

A. are compulsive joggers
B. are encouraged by their doctors to go in for jogging/running
C. are interested in taking more physical exercise
D. are enthusiastic and energetic about hobbies and pastimes

【正确答案】 C

【答案解析】[解析] 由第四段第一、二句可知正确答案为C项。

单选题 In the sentence "In fact, many doctors encourage their patients to become more physically active, especially those who have sedentary jobs", the word "sedentary" means ______.

A. involving physical work
B. needing much sitting
C. energy-consuming
D. sleep-producing

【正确答案】 B

【答案解析】[解析] 根据上下文理解词义。只有B项符合题意。

单选题 According to the passage, will the love for physical exercise last long for Americans?

A. Yes.
B. No.
C. Somebody can tell.
D. It is hard to tell.

【正确答案】 D

【答案解析】[解析] 从最后一段的“Only time can tell”可知D项为正确答案。