据测算阔叶林3天可以放出氧气2.19吨,照这样计算一个月可以放出多少吨氧气?(以30天计)
2.19÷3×30
=0.73×30,
=21.9(吨).
答:一个月可以放出21.9吨氧气.
在艺术字中,有些汉字是轴对称的,下列不是轴对称的汉字是( )
A.田
B.中
C.王
D.上
When I was a student, I ______ to school ______ the bus
A.used to going , by
B.used to go , on
C.used to go, by
D.was used to go, on