根据句意用适当的单词填空。

1.—_____ this?—_____ a notebook.

2.—Is this_____ English book?—_____, it is.

3.It _____a clock. It's_____watch.

4. _____ is a girl.Her name _____ Lily.

5.He_____a boy. _____ name is David.

简述现代医学模式的意义。