Look！The ground is wet.It must have rained last night，________？
| A．hasn’t it | B．didn’t it |
| C．mustn’t it | D．hadn’t it |
The good thing about today’s children is that they can_____ very easily to new environments.
| A．attain | B．allocate | C．adapt | D．adopt |
As a teacher, it is my _________ to make the students devoted to their study.
| A．responsibility | B．affection |
| C．performance | D．judgment |
The research lacksevidence，and therefore，its conclusions are doubtful.
| A．solid | B．fierce | C．severe | D．potential |
A good friend should be kind and helpful. _________ is my mother.
| A．A such friend | B．One such friend |
| C．Any such friend | D．Such one friend |
Though he is ill，he has not quit.
| A．smoke | B．to smoke | C．smoked | D．smoking |