Mr. Smith _______with the government for 40 years by the time he retired.
A. would have worked
B. has worked
C. could have worked
D. had worked
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He will come to see you the moment he _______ his work.
A. finishes
B. had finished
C. would finished
D. will finish
Do not disturb me. I_______ letters all morning and have written ten so far.
A. have been writing
B. have written
C. am writing
D. was writing
This is the third time we _______ improvements in that equipment.
A. are making
B. made
C. have made
D. will make
It’s high time we ______ that old machine.
A. have repaired
B. repaired
C. will repair
D. should have repaired
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