下列说法正确的是（   ）

根尖结构中，根吸收水分和无机盐的主要部位是（   ）

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____.