The old scientist devoted most of his time __________ the space science.
| A．develop | B．to developing |
| C．to develop | D．developing |
When I got home last night, my parents ____ for me at the table.
| A．wait | B．waited | C．were waiting | D．have waited |
How are you now? Go to see the doctor ____ you don’t feel well.
| A．and | B．if | C．or | D．so |
––Beijing is a big city, isn’t it?
––Yes. In fact, it’s one of ____ cities in the world.
| A．big | B．bigger | C．biggest | D．the biggest |
––Why are you late, dad?
––I met a friend and we ____ in the street for a while.
| A．talk | B．are talking | C．talked | D．will talk |
––Where’s your Mom, Xiao Hong?
––She ____ to music in her room.
| A．listen | B．listens | C．is listening | D．has listened |