阅读理解。 Footrace (竞走) is a popular activi

题目：

阅读理解。

     Footrace (竞走) is a popular activity in the United States. It is not only seen as a competitive sport,

but also as a way to exercise, and to donate (捐赠) money to a good cause. Though serious runners

may spend months training to compete, other runners and walkers might not train at all. Those not

competing to win might run in an effort to beat their own time, or simply to enjoy the fun and exercise.

People of all ages, from those less than one year old to those in their 80s, enter into this sport. The races

are held on city streets, on college campuses,through parks, and in suburban areas, and commonly 5 to

10 kilometers in length.

     The largest footrace in the world is the 12-kilometer Bay to Breakers race that is held in San Francisco every spring. This race begins on the east side of the city near San Francisco Bay and ends on the west

side at the Pacific Ocean. In 1993 there were 80,000 people running in this race through the streets and

hills of San Francisco. In the front are the serious runners who compete to win,and who might finish in as

little as 34 minutes. Behind them are the thousands who take several hours to finish. In the back of the race are those who wear costumes just for fun. In 1993 there was a group of men all of whom dressed up like Elvis Priestly. There was a group of firefighters who were all tied in a long line and were carrying a

fire-hose (水龙带). One year there was a wedding party in which the bride dressed in a long white gown (长袍) and the groom wore a tuxedo (晚礼服). They threw flowers to by-standers, and were actually

married at some point along the route.

1. The main purpose of this text is to __________．

A. describe a popular activity

B. encourage people to exercise

C. make fun of runners in costume

D. give reasons for the popularity of footraces

2. Which of the following is implied by the author?

A. Walkers don't compete for prizes．    

B. Footraces appeal to a variety of people．

C. Entering a race is a way to make friends．

D. Running is a good way to strengthen the heart．

3. The underlined words "to a good cause" in the first paragraph could best be replaced by __________.

A. for a good reason

B. to support a sound principle

C. for a good purpose

D. to protect an excellent player