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____.

美国加利福尼亚南部，距东北部的主要市场很远，但农业生产的集约化程度高，其农产品大量销往美国东北部市场，其主要因素是（　）