问题
选择题
区别溶液和胶体最简单的方法是( )。
A．观察外观
B．丁达尔现象
C．布朗运动
D．加热
答案
答案：B
考查胶体的性质及鉴别
胶体具有丁达尔现象，而溶液无些现象，故答案为B
搜题请搜索小程序“爱下问搜题”
区别溶液和胶体最简单的方法是( )。
A．观察外观
B．丁达尔现象
C．布朗运动
D．加热
答案：B
考查胶体的性质及鉴别
胶体具有丁达尔现象，而溶液无些现象，故答案为B
| 选择适当的词语替换句子中的划线部分。 |
| 1. Tom walks to school every day. |
[ ] |
| A. on foot B. goes to C. goes to … on foot |
| 2. There are over 50 students in our class. |
[ ] |
| A. about B. more than C. around |
| 3. We had a good time in the park yesterday. |
[ ] |
| A. enjoyed myself B. have fun C. enjoyed ourselves. |
| 4. The summer holiday goes on from July to September. |
[ ] |
| A. starts B. takes C. lasts |
| 5. I got a letter from my friend last week. |
[ ] |
| A. received from B. heard from C. heard a letter from |