Schools in the cities are well equipped those in the countryside are poor．
A．if B．while C．so D．as
I received a letter， poor spelling made me think it was written by a child．
A．which B．that C．whose D．who
The new online library makes possible for students to choose books by smart phone off campus．
A．it B．one C．that D．this
We were delayed at the airport．Otherwise，we here by lunch．
A．must have been B．could be
C．should be D．would have been
According to the latest study，most traffic accidents be prevented if drivers are careful enough．
A．must B．can C．have to D．need
He never complains about the difficulties he has in life． ，he always has ways to overcome them．
A．However B．Otherwise C．Instead D．Therefore
