1 . The children were heard ________ (sing) in their dormitory last night.

2 . Can you hear Mary ________ (sing) in the room now?

3 . 我经过她房间时听见她在弹钢琴。 （past）
I heard him ________ her room.

4 . When I arrived at the music center in our school, I heard some students ________ (sing) there.

5 . 当我走出厨房的时候，听见有人敲门。
When I got out of the kitchen, I heard someone ________ ________ the door.

6 . —According to the legend, sailors could hear mermaids ________ in the night each time they sailed across that part of the sea.
—Right. People were afraid, so they ________ in many gods at that time.

A．sang; believe

B．are singing; believed

C．singing; were believing

D．sing; believed

7 . —I heard William ________ when I came into the classroom.
—Yes, and then everybody was staring at him.

A．laughed

B．laugh

C．laughing

8 . — Wow, our head teacher is singing the song so beautifully.
— Yes, I never heard her ________ like this before.

A．sing

B．singing

C．to sing

D．sang

9 . When I passed by the hall, I heard many students ________ the musical instruments.

A．play

B．playing

C．to play

10 . I heard Bob ________ when I walked past him just now.

A．sing

B．singing

C．sang

D．to sing