难于磁化的铁磁性材料具有（）。
A.低矫顽力
B.低磁导率
C.低磁阻
D.低剩磁
参考答案：B
维吾尔族房屋的大门忌朝东开。
Since accumulations of H2S gas on a ship can be dangerous to personnel，it is important to know that H2S gas is（）.
A.lighter than air
B.heavier than air
C.a yellow gas that is easily recognized
D.mildly toxic
