四、阅读短文,从方框中选择适当的词并用其正确形式填空,使短文通顺、意思完整。(每词限用一次。)
方框内的词：two fit practise because in
Health is important to everyone. What should we do to keep 15. ? One important rule is to exercise every day.
The Smiths try to exercise every day. Mr Smith can not exercise in the morning 16. he must get to his office before seven o'clock. So he runs every evening.
Mrs Smith likes sport too. She walks to work every day and after work she plays different kinds of sports with her friends. She likes yoga(瑜伽) very much and she goes to the yoga class 17. a week.
Bob, their son, is also interested 18. sport. He often goes to school on foot. His favourite sport is basketball. He always 19. playing basketball after school. He wants to be a famous basketball player when he grows up.

15.fit 16.because 17.twice 18.in 19.practises