When the old man        to walk back to his house, the sun       itself behind the mountain.

A. started; had already hidden                    B. had started; had already hidden

C. had started; was hiding                         D. was starting; hid

 More than a dozen students in that school        abroad to study medicine last year.

A. sent                    B. were sent            C. had sent              D. had been sent

 Months ago we sailed ten thousand miles across this open sea, which _______ the Pacific, and we met no storms.

A. was called        B. is called   C. had been called    D. has been called

 Susan decided not to work on the program at home because she didn’t’ want her parents to know what she __________.

A. has done        B. had done        C. was doing          D. is doing

 Nowadays, a large number of women, especially those from the countryside, _________ in the clothing industry.

A. is working        B. works      C. work       D. worked

 The policeman's attention was suddenly caught by a small box which ______ placed under the Minister's car.

A. has been            B. was being         C. had been         D. would be

 Years ago we didn't know this, but recent science ______ that people who don't sleep well soon get ill.

A. showed              B. has shown        C. will show         D. is showing

 They ________ on the program for almost one week before I joined them, and now we ______ it as no good results have come out so far.

A. had been working; are still working       B. had worked; were still working

C. have been working; have worked          D. have worked; are still working

 —Why did you leave that position?

—I        a better position at IBM.

A. offer                   B. offered                C. am offered          D. was offered

 Scientists think that the continents          always where they         today.

A. aren’t; are           B. aren’t; were         C. weren’t; are         D. weren’t; were