在英语学习中，掌握各种时态的正确使用是至关重要的。下面是一些练习题，帮助大家巩固和提高对英语时态的理解与运用能力。

一、选择题

1. I _______ my homework when you called me last night.

A. was doing

B. did

C. am doing

D. have done

答案：A. 从句中的“called”表明动作发生在过去，而主句的动作正在进行，因此用过去进行时。

2. She _______ for two hours by the time we arrived.

A. had been studying

B. has studied

C. studies

D. is studying

答案：A. 根据“by the time”引导的时间状语，表示过去的某个时间点之前已经完成的动作，需用过去完成时。

3. If it rains tomorrow, I _______ at home.

A. will stay

B. would stay

C. stayed

D. stays

答案：A. 条件句中用一般现在时表将来，主句则用一般将来时。

4. By next year, they _______ in this city for five years.

A. will live

B. will be living

C. will have lived

D. have lived

答案：C. 表示到将来某一时刻为止已经完成的动作，需用将来完成时。

5. The teacher told us that the earth _______ around the sun.

A. moves

B. moved

C. is moving

D. was moving

答案：A. 宾语从句中描述的是客观真理或事实，因此用一般现在时。

二、填空题

1. We _______ (visit) our grandparents every weekend unless we _______ (be) too busy.

答案：visit; are

2. By the time he got to the station, the train _______ (leave).

答案：had left

3. I _______ (not finish) my report yet. It _______ (take) me too long.

答案：haven't finished; takes

4. She said she _______ (read) the book twice already.

答案：had read

5. They _______ (live) here since 2010.

答案：have lived

通过以上练习题，希望大家能够更加熟练地掌握英语时态的用法。记住，多做练习是提高语言技能的关键！