Henry works as a teacher now, but he ______ on a farm for three years.
| A．has worked | B．had worked |
| C．had been working | D．worked |
．There has been rising demand for grain as _______ industrial material in spite of the nation’s good harvests.
| A．/ ;an | B．a; an | C．the;an | D．a; / |
At the meeting they discussed different ______ to the study of mathematics.
| A．approaches | B．means | C．methods | D．ways |
．The children were warned of not being too _______ about things you are not supposed to know.
| A．strange | B．amusing | C．curious | D．satisfied |
It was difficult to guess what her _____ to the news would be.
| A．impression | B．comment | C．reaction | D．opinion |
Having been attacked by terrorists，________．
| A．doctors came to their rescue | B．the tall building collapsed |
| C．an emergency measure was taken | D．warnings were given to tourists |