I was out of town at the time, so I don’t know exactly how it _______.

A. was happening        B. happened       C. happens         D. has happened

 My parents _____ in Hong Kong. They were born there and have never lived anywhere else.

A. live         B. lived        C. were living        D. will live

 This is the first time we______ a film in the cinema together as a family.

A. see   B. had seen    C. saw    D. have seen

 Mary went to the box office at lunch time, but all the tickets ______ out.

A. would sell   B. had sold     C. have sold    D. was selling

 During the period of recent terrorist activities, people _______ not to touch any unattended bag.

A. had always been warned                     B. were always being warned

C. are always warning                             D. always warned

 Over the past decades, sea ice     in the Arctic as a result of global warming.

A. had decreased   B. decreased    C. has been decreasing   D. is decreasing

 —What do you think of the movie?

—It’s fantastic. The only pity is that I     the beginning of it.

A. missed   B. had missed   C. miss D. would miss

 She stared at the painting, wondering where she      it.

A. saw   B. has seen   C. sees   D. had seen

 ----I’ve got to go now.

---Must you? I          you could stay for dinner with us.

A. think    B. thought   C. have thought   D. am thinking

 ——Did you see Grace in the teacher’s office？

——Yes, she ______to him why she didn’t hand in her assignments

A. is explaining     B. was explaining    C. had explained     D. explained