Though faced with so many difficulties, they are _____ about their future.
A. curious B. enthusiastic
C. optimistic D. concerned
The Sahara Desert is almost _____ of the US.
A. as big B. the size
C. the area D. the same
We shall never forget the days ________ we spent playing happily together.
A. in which B. which C. when D. on which
______ is said, the Yeti is a large, hairy animal that walks on two feet like a human being.
A. It B. That C. As D. What
It is thought that Zheng He, a Chinese in the Ming Dynasty, may have been the first person who _____________America from the East.
A set out to B. set about to
C. set sail to D. set sail for
I don’t care ____ or not you like the plan.
A. if B. whether C. that D. how
