两明渠均匀流,断面面积、流量、渠底坡度都相同,1号的粗糙系数是2号的2倍,则两者水力半径的比值为:
A.2 B.0.5 C.2.83 D.1.41
参考答案:C
The story ______ me, that is, I am _______ at the ______ story.
A.surprise; surprising; surprised
B.surprises; surprised; surprised
C.surprise; surprised; surprising
D.surprises; surprised; surprising
按存在的风险是否有产生收益的可能可将风险分为( )。
A.纯粹风险
B.投机风险
C.静态风险
D.动态风险
E.经济风险