It is reported that a space station ______ on the moon in years to come.
A. will be building B. will be built
C. has been building D. has been built
The real reason why prices ____ , and still are, too high is complex, and no short discussion can satisfactorily explain this problem.
A. were B. will be
C. have been D. had been
To my delight, I from hundreds of applicants to attend the opening ceremony.
A. was chosen B. was being chosen
C. would choose D. had chosen
—Where is Peter? I can't find him anywhere.
—He went to the library after breakfast and his essay there ever since.
A. wrote B. had written
C. has been writing D. is writing
Mary really hard on his book and thinks he’ll have finished it by Friday.
A. worked B. has been working
C. had worked D. has worked
At college, Barack Obama didn’t know that he the first black president of the United States of America.
A. was to become B. becomes
C. is to become D. became