导线电阻的大小和（）有关
A.长度
B.横截面积
C.材料
D.湿度
参考答案：A, B, C
Lucy has got into a situation in her study ________ she finds it hard to go further.[ ]
A. that
B. where
C. which
D. at which
预计该婴儿的头围应当为
A．58cm
B．50cm
C．48cm
D．44cm
E．34cm
