My father is usually on _______ duty in his office every _______ few days.
| A．the；a | B．/； / | C．/；a | D．a； / |
More expressways in Sichuan soon to promote the local economy.
| A．are being built | B．will be built |
| C．have been built | D．had been built |
The books on the desk, covers are shiny, are prizes for us.
| A．which | B．what | C．whose | D．that |
You _____be careful with the camera. It costs!
| A．must | B．may | C．can | D．will |
That restaurant is extremely popular, ______ you may have to wait to get a seat.
| A．for | B．so |
| C．or | D．yet |
It is so cold that you can’t go outside _____ fully covered in thick clothes.
| A．if | B．unless |
| C．once | D．when |