煤的最大粒度应在何时进行测定（）
A、采样前
B、采样中
C、制样时
参考答案：A
- Why don't you do some shopping in the second-hand store?
-Well, the things there are______, but______.
A．cheaper; good enough
B．cheaper; not as good
C．more expensive; worse
D．more expensive; not as bad
