环枢正中关节属于（）
A.屈戌关节
B.车轴关节
C.椭圆关节
D.鞍状关节
E.球窝关节
参考答案：B
The science of computer, _____rapid progress has been made in recent years, is the most important of all science.
A．to which
B．in which
C．of which
D．from which
若函数y=f(x)的导函数f′(x)=6x2+5，则f(x)可以是______．
A．3x3+5x B．2x2+5x+6C．2x3+5x D．6x3+5x+6
