从冷却水中除去成垢的钙离子的方法主要有() A.离子交换树脂法和石灰软化法 B.加酸 发布时间:2018-05-26 02:18 │ 来源:www.tikuol.com 题型:单项选择题 问题: 从冷却水中除去成垢的钙离子的方法主要有()A.离子交换树脂法和石灰软化法B.加酸或通气C.降低pH值
题型:单项选择题 He was in hospital for six months. He felt as if he were ______ from the outside world.[ ]A. cut downB. cut offC. cut inD. cut through 查看答案