Câu hỏi: ............. the experiment three timesnow with different results each time!

A. We’ve done

B. We did

C. We’ve been doing

Câu 1: When I arrived the lecture .............. so I didn’t find it easy to follow.

A. started

B. had started

C. had been starting

Câu 2: She ................ well at school but thatchanged when she became friends witha different group of girls.

A. did

B. had done

C. had been doing

Câu 3: They.......................personal computers when my father was a student.

A. hadn’t

B. didn’t havecorrect

C. weren’t having

Câu 4: Nina and her friends had a great time, singing and dancing and............. to their favourite music.

A. listening

B. hearing

C. looking

Câu 5: My sister.................... economics andpolitics when she goes to university.

A. is going to study 

B. studies 

C. will study

Câu 6: Most university students.................. on campus in their first year.

A. lives

B. livecorrect

C. are living