All of us found ______ difficult to work out the maths problem.
A. what B. that C. which D. it
By the time these books were published, he _____ addicted to them.
A．had become B. becomes C. has become D.became
I'm fine — I just felt a bit sleepy and tired, that was ________ I went to bed so early."
A. because B. when C. that D. why
—why, Jack, you look so tired!
—Well, I _____the house and I must finish the work tomorrow.
A. was painting B. will be painting C. have painted D. have been painting
—I’ve told Nancy many times about the meeting, but she still forget it!
—I understand. Actually, anyone ______ be very forgetful at times.
A. must B. should C. ought to D. can
Having a trip abroad is certainly good for the old couple, but it remains _____ whether they will enjoy it.
A. to see B. to be seen C. seeing D. seen
