─Do you know_____second-hand smoke? ─To protect our health and memory.
| A．how we should prevent | B．how we should prevent |
| C．why we should prevent | D．whether we should prevent |
Now, people have more free time. Square Dancing is becoming more and more ______.
| A．comfortable | B．difficult | C．different | D．popular |
Going to the movies is good, ______ I really only like listening to music.
| A．and | B．but | C．so | D．or |
We planned to meet at 10:30 at the station last Sunday, but Bob didn’t ______ until 12:00.
| A．turn up | B．give up | C．stay up | D．grow up |
Dreams are beautiful. However, to ______ them needs lots of time and work.
| A．discover | B．find | C．achieve | D．stop |
–Cathy, can you answer the door? I ______ the room. –I’m coming, mum.
| A．clean | B．cleaned | C．have cleaned | D．am cleaning |