【单选题】关于分子筛催化剂的组成和结构表述不正确的是?
A.
分子筛又称为沸石分子筛,是一种水合结晶型硅铝酸盐;
B.
沸石分子筛对许多酸催化反应具有高活性和异常的选择性;
C.
分子筛催化剂的化学通式为M x/n [(AlO 4 ) x ·(SiO 2 ) y ] ·zH 2 O,晶体内的阳离子和水分子在骨架中有很大的移动自由度,可进行阳离子交换和可逆的脱水。
D.
分子筛因可根据其晶体内部孔穴的大小对分子进行选择性吸附,因此被形象地称为“分子筛”;
E.
各种分子筛最根本的区别是化学组成不同,因而不同组成的分子筛具有不同的性质。
【简答题】What's the man's opinion on watching TV? [A]It is not only for entertainment. [B]It makes people relaxed. [C]It is not good to eyes.
【判断题】分子筛是大量蛋白聚糖聚合体形成的有许多微孔的结构。
【单选题】疏松结缔组织中形成分子筛结构,对物质进行选择性透过的是
【单选题】— What's in the ______________? — A TV. [ ]
【判断题】(What’s Wrong with Our Press?) The author thinks that one of TV’s advantage over papers is its wide range of entertainment for the public. ()
【单选题】—What's on TV tonight? —There's _____. It's boring. [ ]
C.
everything interesting
【简答题】She has got this (obsess) fear of losing control, so she never shows her emotions
【单选题】What‘s the man‘s opinion on watching TV? 查看材料
A.
It is not only for entertainment.
B.
It makes people relaxed.
C.
It is not good to eyes.
【单选题】After the fashion show, she was always ________ the beautiful clothes.