10. It’s important to keep the b_______ of nature.

9. It is important to know your own w____________.

8. Many scientists are doing r_______ into the cause of this strange illness.

7. Xiao Wang felt frustrated that a lot of c_____ went to a newly-opened small restaurant.

6. Foods for the old should be easy to be d_________.

5. We all a________ her for the way she saved the children from the fire.

4. We classmates visited our beloved teacher on hearing his a___ in the capital city.

3. I don’t mind a_____ to others if I make a mistake.

2. For lack of food, the old man s_____ to death.

1. To s_________ his parents, he always works very hard.