搜题请搜索小程序“爱下问搜题”
问题 选择题

向Ca(OH)2饱和溶液中加入少量CaO，若温度保持不变，下列叙述正确的是 [ ]

A．溶液质量不变

B．溶液中溶质质量增多

C．溶液中溶剂质量不变

D．溶液浓度不变

答案

答案：D

选择题

Mike has put on so much weight this year that his mother has to________all his trousers to his measure. [ ]

A. let out

B. give away

C. bring in

D. lay out
查看答案
单项选择题

截止阀的安装，有着严格的方向限制，其原则是“（）”。

A、高进低出

B、低进高

C、高进中出

D、中进低出
查看答案