He wrote a letter ________ he explained what had happened in the accident.
A. that B. which
C. where D. what
The fellow we spoke ________ no comment at first.
A. to make B. to made
C. made D. to making
—What a pity! You missed my birthday party.
—Terribly sorry! ________ my uncle not visited me unexpectedly.
A. Should B. Would
C. Had D. Did
China’s Chang’e 4 robotic probe entered lunar orbit on Wednesday, ________ a major step in its mission to make a soft landing on the moon’s far side.
A. marking B. to mark
C. having marked D. marked
—It’s really great to have a computer to store my photos.
—Don’t count on it too much. It ________ break down and you’d better make a copy of them.
A. must B. can
C. should D. will
—Julia said she sent you a birthday card yesterday. Have you got it?
—Oh, really! I haven’t ________ my mailbox yet.
A. examined B. reviewed.
C. tested D. checked
