Ecogenesis
生态种的发生, 生态史, 生态进化
🗣️ 情景例句
How many courses are you taking this semester?
这学期你选了多少课？
It's raining.
外面下着雨。
Fortunately, however, ancient men made tools of stone, especially flint,
然而， 幸运的是，远古人用石头制作了工具，特别是用燧石，