甲醇合成气中,CO:22.24%、CO2:5.86%、H264.87%,合成气的氢碳比是()。
参考答案:2.1
____ is to be done is ______ to carry it out smoothly since the decision has been made.
A.What; how
B.Where; how
C.When; what
D.Where; what
对于声级起伏较大的非稳态噪声或间歇性噪声,采用()为评价量。
A.A声级
B.最大A声级
C.等效连续A声级
D.计权等效连续感觉噪声级