1. (2017·深圳模拟) 读句子，选择适当的词组完成句子。

more than   having a barbecue   in danger   on foot   keep quiet

1. （1） Look! The people are . We must help them.

3. （2） There are fifty pupils in the classroom.

5. （3） I usually go to school .

7. （4） We must in the library.

9. （5） is my favourite outdoor activity.