Metapopulation
集合种群
🗣️ 情景例句
Then you have to fill out this form
然后你要填写这份表格，
When the tree is fallen, every one runs to it with his axe.
大树一倒下，人人持斧来。
People travelling long distances frequently have to decide whether they would prefer to go by land, sea, or air.
出远门的人常常需要决定是走旱路、水路，还是坐飞机。