With many cities in China dreadfully blanketed by thick haze, the environment problem is _____ Chinese people concern most nowadays.
| A．what | B．which |
| C．where | D．when |
More than one teacher _____ told him it is important that he learn English well if he _____ aboard.
| A．have; shall go | B．has; want to go | C．has; wants to go | D．had; will go |
The meeting was _____ at ten o’clock, but the chairman hadn’t turned up by eleven o’clock.
| A．start | B．have started | C．be starting | D．be started |
The last half of the nineteenth century _____ the steady improvement in the meansof travel.
| A．has witnessed | B．was witnessed | C．witnessed | D．is witnessed |
Once environment damage _____, it takes many years for the system to recover.
| A．has done | B．is to do | C．does | D．is done |
As _____ announced in today's papers, the Shanghai Export Commoditiser Fair is also openon Sunday.
| A．being | B．is | C．to be | D．been |