室内空气污染的甲醛主要来自
A.装饰材料B.建筑材料C.吸烟D.燃料燃烧E.烹调油烟
参考答案:A
下列实验中,能证明苯酚的酸性极弱的是 [ ]
A.跟氢氧化钠溶液反应生成苯酚钠
B.跟FeCl3溶液作用显紫色
C.二氧化碳通入苯酸钠溶液能产生苯酚
D.常温下苯酚在水中溶解度不大
写出下列各句的同义句。
1. Li Ming and his parents had a good time in Shanghai last summer.
Li Ming and his parents _______ _______ in Shanghai last summer.
2. Linda is old enough to look after herself.
Linda is old enough to _______ _______ of herself.
3. You mustn't feed the animals in the zoo.
_______ _______ the animals in the zoo.
4. The black printer is cheaper than the other printers in the shop.
The black printer is _______ _______ of all the printers in the shop.
5. Last week, I got a letter from a friend of mine.
Last week, I _______ _______ a friend of mine.