Ecosystems
n. <生>生態系統( ecosystem的復數形式 )
??? 情景例句
Then an adult must sign for you.
那就必須有一位成年人來替你簽字。
What in the world are you eating?
你到底在吃什么？
'Well, I'd prefer to stay here,' I said.
“可我更愿意呆在這兒，”我說，