对于泥浆护壁成孔时泥浆作用的不正确说法是()。
A.浮碴
B.减少土的含水量
C.护壁
D.防止流沙
参考答案:B
命题“对∀x∈R,x3-x2+1<0”的否定是______.
I'm afraid he’s more of a talker than a doer, which is ____ he never finishes anything.
A.that
B.when
C.where
D.why