资源看点：对所学基础知识进行全面训练，同步实用。

II. 单项选择。

选择正确的答案填空。

(  )11. The United Nations is based in ______.

A. Washington       B. Tokyo        C. London       D. New York

(  )12. All the students are studying hard. They are always preparing _____ for our country.

A. to work          B. working       C. works        D. worked

(  )13. Many animals can work for people. They can do something as they _____.

A. are telling         B. tell          C. are told       D. told

(  )14. I saw her _____ on the sidewalk when I drove by the road.

A. was walking      B. walking       C. walked        D. walks