The term “erosion” refers to_______.

A.Osgood's term of employment is longer han that of any other work

B.no other employee has worked in the factory as long as Osgood

C.the factory has no employee who has worked as long as Osgood

D.Osgood has worked at the factory longer than any other employee

Term牙歹q{旨数是{旨

A.上颌牙列的长度

B.上下牙列的宽度的比值

C.牙列的宽度与长度的比值

D.上下牙列的长度的比值

E.下牙列长度与宽度的比值

证明=r(A)+r(B)。

证明函数在任何区间(-R,R)，(R＞0)上不能展开成幂级数

电荷Q均匀分布在半径为R的球体内,试证明离球心r处(r＜R)的电势为

A.r+s

B.r-s

C.r×s

D.MAX(r,s)

设R是一个环，u∈R。证明R对于以下二个运算

作成一个环与原来的环R同构。

计算积分其中r＞0，n是整数，|a|≠R。

A.V1导联R/S<1

B.v5导联r/s>1

C.aVR导联R波<0.5mV

D.aVL导联R波<1.2mV

E.aVF导联R波<1.0mV