矿物表面润湿接触角与矿物的可浮性关系，接触角小，则矿物的（），难浮。
A、亲水性弱
B、疏水性强
C、亲水性强
D、疏水性弱
参考答案：D
. —Why do you ____ very happy this afternoon?
—Because we are going to spend the evening at Lily’s house.
A．taste
B．sound
C．look
D．smell
我段防洪抢险规定各检修队应备防洪料具中：捣固锤（）个。
A.2
B.5
C.10
D.15
