water is there in the river?
does your school organize an English speech contest?
for us to plant trees every year.
having a picnic at the weekend?
your brother milk every day?
Almost all people think exercising is good for us. But how often should (应该) we exercise? Five days week? Four days week? Is two days week 1? Luckily, the answer 2 the question is not difficult to find.
We asked Shawn Arent, a scientist (科学家), about this question. He said that people should 3 every day. It really does great help to our 4 and health.
Shawn also told us 5 more interesting "There is a big 6 between exercising two days a week and three days a week," Shawn said. "With three days a week, your body gets enough exercise and you want to do 7 activities to be healthier (更健康的). 8, with two days week, you don't get much change (改变). You just don't do it often enough, so you can't fully (完全地) 9 the fun of exercising.
"For children and old people, it's a good start to exercise two days a 10 at first. But I still want them to exercise more after some time. Three to four days a week will be wonderful for them," Shawn said.
(A)You can make your body healthy by bathing. Do you know? It was popular hundreds of years ago. Modern bathing with medicine or hydropathy（水疗法）first became popular in America. For many years people thought if you always bathed, it was bad for health. They didn't think bathing every day just to keep clean was good idea. By the 18th century some doctors started to think that soap and water were good for health. They believed that it was good for people to be clean. (B) During the late 19th century, you would see a lot of families take a bath on Saturday night.
In America bathing every day was slow to become popular. During the 18th and early 19th centuries, Americans hardly ever washed. In one American city, for example, a man could only take a bath every thirty days. That was a law（法律）.
(C) Now it is a habit for people to bath every day. People know that bathing can make them clean and it is important for their health. Doctors know that dirty bodies can get ill easier. Today in America people bathe, and some even bathe once a day.
