室温下,饱和食盐水露置在空气中一段时间后有少量固体析出,下列说法正确的是[ ]
A、溶剂质量减少了
B、溶液仍为饱和溶液
C、氯化钠的溶解度变小
D、溶质的质量分数变小了
AB
It is suggested that a doctor ____immediately.
A.be sent for
B.send for
C.is sent for
D.should send for
简述牙轮钻机提升加压封闭链条是怎样缠绕的?