________Beijing you see today is quite ________ different city from what it used to be.
| A．The; / | B．/; the | C．The; a | D．A; a |
_A container weighs more after air is put in, ____proves that air has weight.
| A．as | B．it | C．that | D．which |
_)I had not believed in falling in love with somebody at first sight_______I met David on Valentine’s Day three years ago.
| A．when | B．unless | C．if | D．before |
_—Did you visit the Summer Palace?
—No.We could have, _______we spent too much time shopping.
A.so B but C.ecause D.though
_______is often the case,he succeeded in this examination again.
| A．What | B．So | C．Which | D．As |
_ _______broken,the glass can not hold water.
| A．Once | B．After | C．On | D．Though |