No government can justly claim authority ______ it is based on the will of the people．
| A．unless | B．after | C．so that | D．while |
______ with a moon rover(月球车) called “Yutu” (Jade Rabbit) , Chang'e-3 successfully landed on the moon.
| A．Being equipped | B．Having equipped | C．To be equipped | D．Equipped |
All their attempts to rescue the child from the burning building were _____, and he died soon.
| A．in place | B．in return | C．in vain | D．in ruins |
Be careful when you cross this busy street. _____, you may get run over by a car.
| A．If not | B．If so | C．If any | D．if possible |
Smoking is so harmful to people’s health that it kills __________ people each year than automobile accidents.
| A．seven more times | B．seven times more | C．over seven times | D．seven times |
I’ll come to pay a visit to you if _______ this weekend.
| A．you’re convenient | B．it is convenient for you |
| C．you feel convenient | D．it is convenient with you |