例句：

　　Exercise tones up your body.

　　運(yùn)動(dòng)強(qiáng)健身體。

　　Riding a bike is great exercise.

　　騎自行車是很好的'鍛煉。

　　Swimming is good exercise.

　　游泳是有益的運(yùn)動(dòng)。

　　How often do you exercise?

　　你多長時(shí)間鍛煉一次？

　　Swimming is a good form of exercise.

　　游泳是很好的鍛煉方式。