采集有组织排放的污染物时，采样管应插入烟道（或排气筒）近中心位置，进口与排气流动方向成直角，如用b型采样管，其斜切口应背向气流（）
参考答案：对
Teaching and learning are parts of the same educational experience, but unfortunately they are often thought of ___________ separate.
A．as if
B．being
C．as
D．like
压缩机气缸的余隙有何作用？
