最简单的电路不包括()。
A.电源
B.过载保护器
C.开关
D.导线
参考答案:B
It was lack of effort , not of money , _______resulted in their failure. [ ]
A. as
B. which
C. that
D. what
橄榄-脑桥-小脑变性的代托综合征(Dejerine-Thomas)型系指()
A.散发性
B.遗传性
C.混合型
D.无脊髓受累型
E.以上均不正确