天然气的动力粘度的法定单位是()
(A)帕秒;
(B)泊;
(C)托;
(D)毫托秒
参考答案：A
用适当的关系代词或关系副词完成下列句子。
1. I hope to visit a place_____ the weather is cool.
2. The village in_____ my grandparents used to live lies at the foot of a mountain.
3. I know a place_____we can have a wonderful time.
4. The girl_____ is standing there is my sister.
5. Do you like the shirt_____ is very expensive?
用自然沉降法测定空气中细菌总数，将营养琼脂平板置于采样点处，打开平皿应暴露（）。
A.2分钟
B.4分钟
C.5分钟
D.8分钟
E.10分钟
very expensive?