—When can I call on you, afternoon or evening? —________. I’ll be at home all the time.
What the monitor said at the class meeting ________ quite all right.
The room ________often cleaned by the students.
A . key
B . they
C . obey
D . grey
I am very _______ to you for your help.
从0,1,2,3,4,5这六个数字中,每次取出三个数相乘,可以得到不同乘积的个数是( )
Oceania is a________ landmass.
设集合M={X∈R|X≤-1},集合N={∈R|Z≥-3},则集合MnN=( )
用单色光照射金属表面,使金属释放光电子,增大单色光的频率,但同时减小它的强度,则光电子的实际动能( )