A:What
B:When
C:Where
某工厂有一根圆柱形铁皮烟囱,底面直径是6分米,高是25分米,现要将烟囱加高到30分米,至少还需要铁皮多少平方分米?
Remember ____ (turn off) the light when you leave the room.
下列典故中体现孝敬父母传统美德的是( )