zuo luo gua xia
“If the government does not give any feedback or does not release a final report of the survey, the respondents will think they participated _______," said the social scientist Hu.
A.in no way
B.in vain
C.without effort
D.at a loss
某一泥石流经实测其容重为l9kN/m3,固体物质的容重为24kN/m3,泥石流沟的清水汇人流量为40m3/s,取泥石流的堵塞系数为2,按汇水面积法计算泥石流的流量约为()m3,/s。
A.240
B.300
C.360
D.400