电力变压器结构形式有各种不同分类方法,按绝缘介质可分为( )。
A.心式变压器
B.空气冷却变压器
C.油浸式变压器
D.干式(空气绝缘、SP6气体绝缘)变压器
参考答案:C,D
从事动物产品购销、贮存、冷藏、加工、运输等称动物产品的()活到。
A、生产
B、经营
China won 100 medals in the Beijing Olympic Games, which are almost ______ those of the Sydney Olympic Games.
A.twice as many as
B.as many as twice
C.as much as twice
D.twice as much as