Have you finished your work yet?—No，not yet. I think it’ll take ________ minutes.

The girl sat in the corner _____ quietly _____ none of us noticed she was there. [ ]

Don’t just wait for other’s help. God help those who help .

Make sure all the lights ______ when you leave the room.— OK, I will.

There is somebody knocking at the door. Who________ it be?—I’m not sure. It ________ be a postman.