架空导线间距不小于()。
A.200mm
B.300mm
C.500mm
D.600mm
参考答案:B
用所给词的适当形式填空。
1. I found myself ____( surround) by a group of children.
2. When she came to life,she found herself _____(lie)in hospital.
3. He was found _____(die)in the morning.
量结果和实际值之差与实际值之比称为()。
A.绝对误差
B.相对误差
C.比值误差
D.引用相对误差