C:用渗析的方法净化胶体时,使用的半透膜只能让较小的分子、离子通过
A:布朗运动是胶体微粒特有的运动方式,可以据此把胶体和溶液区别开来
B:光线透过胶体时,会发生丁达尔效应
D:胶体微粒能吸附阳离子或阴离子,故在电场作用下会产生电泳现象
用“who”或“that”填空(1) The man____ is talking with my mother is my father .(2) That book is the one____ I bought yesterday .(3) He is one of the workers ____ been saved in that accident .(4) They talked of the things and persons ____ they remembered in the factory .(5) All____ can be done must be done .
唐王朝社会结构分为贵族和平民两部分,而平民包括两个部分:庶民和贱民。贵族跟平民的等级是严格的,只有一条似有似无的狭径,作为庶民爬上贵族地位的阶梯…… 这里的“狭径”主要是指