当砌块砌体的竖向灰缝宽度为()时,应采用C20以上细石混凝土填实。
A.15~20㎜
B.20~30㎜
C.30~150㎜
D.150~300㎜
参考答案:C, D
The father is telling his son ______ on New Year Eve. They're going to listen to the New Year clock. [ ]
A. not fall asleep
B. not to fall asleep
C. to not fall asleep
D. to fall not asleep
什么叫仰视图?