去帮我看看这英语翻译
我这暑假预习,很多不明白请多多包涵
1.do exercise = exercise 吗
2.how often .回答用 once /twice/three time a week ,怎么once /twice表示1/2,为什么3用three time a week 表示?
3.He tries riding the bike himself.bike himself什么意思
4.Having too much sugar and fat is not a good eating habit.
Eating more fruits can let us keep in good health.
这开头为什么加ing.
5.very active /very often各什么意思.