补全对话(共5小题；每小题1分，满分5分)   根据对话内容，从方框内的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

A: Hello, Ann .  __1.____              B: Because I walk to school today.

A:        2.                       B: By bike. _____3._____

A: I’m sorry to hear that. ___4.__ _      B: All of them live near our school, so they usually walk.

A: __________5._____ _              B: By bus

A: Does anybody come by car?            B: No, I don’t think so.

Trees are useful to man（人类）in three very important ways. The first important way is that they provide man with food, wood and other products. Trees provide not only man with food, but also many animals with food. Without trees many animals could not live on the earth. It's not easy for man to live on the earth, either.
The second important way is that trees give us shade. On a hot summer day, people are eager(渴望)to have a rest under the shade of a tree after they have walked a long way. You can imagine how important the shade of a tree is to man and to animals.
The third important way is that trees help to prevent drought（干旱）and floods（洪水）. However, in many parts of the world, man has not realized the third important way. He has cut trees down in large numbers. In the end he finds that he has lost the best friends he had.
【小题1】Trees are important to man in       ways.

The keys to reaching or staying at a healthy weight are regular exercise and good eating habits. Teens should get 60 minutes or more of physical activity a day. Note the word “activity”. As long as you’re getting your body moving, it doesn’t have to mean doing difficult exercise or going to the sports hall every day. All that matters is that each week you get the right balance of activity, including aerobics (有氧运动), strength building, and flexibility (柔韧) exercise. Make exercise a habit by arranging some time every day.

On days when you have soccer practice or an aerobics class, you may have no trouble exercising for an hour or more. But most of us are busy, and 60 minutes a day for exercise seems like a lot of time. The good news is that it’s OK to divide it into shorter exercise breaks throughout the day.

Just as you might have a healthy snack to stop yourself from getting hungry, exercise snacks can keep energy levels high. So get up 15 minutes early and do some stretching (伸展) activity. Walk fast or run slowly for 15 minutes after lunch. Do the same thing after school — or walk or bike home. Add to that taking the stairs, PE class, and walking between classes during the day, and you’ve probably reached your 60 minutes.

Here are five simple ways to make an exercise lifestyle change:

1.The writer thinks many people probably misunderstand the word“activity” to be “_______”.  

2.When exercising, the most important fact is ________.

3.The author advises dividing activity into shorter exercise breaks because ___.

4.What’s the best title for this passage?