A:体内受精
B:卵生
C:水中发育
D:变态发育
①制作酸奶 ②制作米酒 ③制醋 ④生产青霉素 ⑤制作面包.
一元钱硬币的直径约为24mm,则用它能完全覆盖住的正六边形的边长最大不能超过( )
下列关于两栖动物的描述中不正确的是( )
Our government has tried many ways to the smog(雾霾)problem. Maybe we'll have a clear sky in the near future.