阅读以下语篇，掌握其大意，然后从各题所给的A、B、C、D四个选项中选出最佳选项。

Americans love to do sports. 1 they are not full, they usually do exercise. Many do exercise at 2 five times a week. If they are busy, they often do exercise 3 or three times a week.

4 do they love sports so much? Many of them are very fat. Being fat

5 them lots of problems, so they want to play sports to keep 6. At the same time, some people may lose their jobs 7 being too fat. So it's important for them to do exercise. Sports lovers usually do their work 8.

Outdoor 9 are also their favorites. Usually the whole family goes out together when they are 10. And staying with parents more is good for children to grow up healthily.