A：Time and tide waits for no man.
B：Many a student are busy with their lessons.
C：As is known to all, Rocky mountains stand in North America.
D：The singer and dancer is to attend our party.
半圆的半径是5厘米，半圆的周长是( )厘米
在生物分类的等级单位中，生物之间共同特征最少和亲缘关系最近的分别是（ ）
—It's 100 yuan.
