在竖井内如空气温度高于室外，空气的密度随之出现差别，由于浮力作用将导致烟囱效应。（）
参考答案：对
基本语法
1. SuCh things can no__________(long) be allowed to go on.
2. The old woman used__________(be) kind to those animals.
3. __________(difficult) the questions are,__________(likely)I am to be able to answer them.
4. He would rather__________( listen) to others than __________(talk) himself.
5. Tom was willing __________(learn)to play chess with me.
常温下，用 0.1000 mol·L-1NaOH溶液滴定 20.00mL0.1000 mol·L-1 CH3COOH溶液所得滴定曲线如图。下列说法正确的是
A．滴定过程中可能出现：c(CH3COO-)>c(Na+)>c(CH3COOH)>c (H+)> c(OH-）
B．点①所示溶液中酸的中和率大于50%
C．点②是二者恰好中和点
D．点③所示溶液中：c(Na+)> c(OH-)> c(CH3COO-)>c (H+)
