问题
选择题
进行化学实验必须注意安全,下列说法不正确的是
[ ]
A.点燃氢气前要检验纯度,以免发生爆炸
B.不慎将浓盐酸溅到皮肤上,要立即用浓碱溶液冲洗
C.CO气体有毒,处理CO尾气的方法一般是将其点燃,转化成无毒的CO2
D.在盛O2的集气瓶中进行铁丝燃烧实验时,事先在集气瓶底部铺上一层沙子
答案
答案:B
进行化学实验必须注意安全,下列说法不正确的是
[ ]
A.点燃氢气前要检验纯度,以免发生爆炸
B.不慎将浓盐酸溅到皮肤上,要立即用浓碱溶液冲洗
C.CO气体有毒,处理CO尾气的方法一般是将其点燃,转化成无毒的CO2
D.在盛O2的集气瓶中进行铁丝燃烧实验时,事先在集气瓶底部铺上一层沙子
答案:B
选用方框中所给单词的适当形式填空。 | |
1. We _________ ourselves quite a lot at the party. 2. The ________clothes haven't been washed yet. 3. Guangzhou _______in the south of China. 4. John got _________ to Mary. 5. There is no _________ of oil paintings here. 6. Lots of western people are interested in_____culture. 7. __________, everyone can have a great life. |