________ you’ve tried yourself, you’ll never know what an exciting game bungee jumping is.
| A．Though | B．Because | C．Unless | D．If |
8．Without your kind help, we ______ in the experiment.
| A．cannot succeed | B．hadn’t succeeded |
| C．w ouldn’t succeed | D．couldn’t have succeeded |
7．Since you are here, you ____ as well stay here for long.
| A．can | B．may | C．must | D．Should |
6．What ______ great progress you have achieved in such ____ short time!
| A．a ; a | B．/ ; a | C．/ ; / | D．a; the |
5．The little kid can help himself _____ his favorite toys.
| A．to | B．in | C．for | D．On |
4．My hands are dirty. I ______ the wall the whole morning but haven’t finished yet.
| A．have painted | B．have been painting | C．am painting | D．Painted |