A：胶体区别于其它分散系的本质特征是具有丁达尔现象
B：煤的气化、石油分馏、海水制镁、海带提碘等过程中都包含化学变化
C：发酵粉能使焙制出的糕点疏松多孔，是因为发酵粉中含有碳酸氢钠
D：加碘食盐中添加碘酸钾而不用碘化钾，是因为碘酸钾能溶于水而碘化钾不溶于水
下列运输任务与适宜的运输方式搭配正确的是（ ）
根据句意及首字母提示完成单词
① Paper can be r____. We'd better not throw it away.
② It is important to try to save e____.
③If we don't protect our e____, the earth will be destroyed.
④ Our teacher tells us to collect r____ plastic bags.
⑤ Gold, silver and iron are all m____.
