In some developed countries, larger population is ______________ in their big cities.

A．approved         B．gathered          C．concentrated       D．fixed

Had it been possible I would have gone to the movies, but I ________________ busy.

A．had been         B．am               C．was              D．would be

 We lost our way in that small village, otherwise we ________more places of interest yesterday.

A．visited                                B．had visited

C．would visit                             D．would have visited

 Mothers holding jobs outside the home should have _______ schedules to make it easier to care for their children.

A．heavy            B．smooth           C．flexible           D．complex

Some insects ______ the colour of their surroundings to protect themselves.

A．take in            B．take off           C．take on           D．take up

----How did you like Nick’s performance last night? ----To be honest, his singing didn’t _______to me much.

A．appeal            B．belong            C．refer             D．occur

 —Was it under the tree _______ you were away talking to a friend?

—Sure. But when I got back there, the bike was gone.

A．that              B．where            C．which            D．while

 Einstein’s Theory of Relativity was so __________that few people could understand it at that time.

A．controversial       B．religious          C．abstract           D．contradictory

—Mary was being badly treated when John happened to pass by and helped her out.

—I think it was not a pure ________but had been well planned.

A．coincidence       B．consequence       C．incident           D．chance