正确的实验操作是科学探究成功的基础。下列操作中正确的是 [ ]
A．
B．
C．
D．
答案：C
--- He is a very hard-working student．
---________．As far as I know, he often burns the midnight oil．
A．You can say that again
B．Absolutely not
C．Heaven knows
D．No way
46,33,22,15,10，（）。
A．1
B．3
C． 5
D．7
