unsigned char、unsigned int等类型的长度是( )
A. 固定的
B. 由用户自己定义的
C. 任意的
D. 与机器字的长度有关的
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
The research is so designed that once _______ nothing can be done to change it.
A. begins
B. having begun
C. beginning
D. Begun
It is said that in Australia there is more land than the government knows _______.
A. it what to do with
B. what to do it with
C. what to do with it
D. to do what with it