根据句意及汉语提示填空

1. I really enjoy the music. It sounds so _______(令人愉快).

2. I felt very _______(难过), because he hurt my dog.

3. Here's some _______(有用的) information about travel in Canada.

4. —Do you wash _______(碟子) at home?

    —Yes, but not often.

5. The teacher told us a funny story. All the students _______(笑了) happily.

联合应用两种药物，其总的作用大于各药单独作用的代数和，这种作用叫做（）

A.增强作用

B.相加作用

C.协同作用

D.互补作用

E.拮抗作用