— How old is Mr. Gao?
— He is more than thirty. I think he was born _________.
A:in the 1980
B:in the 1980s
C:on the 1980
D:on the 1980s
我国四大区域中人口最少的是( )
“樱桃好吃树难栽,不下苦功花不开”,其中樱桃的可食用部分由花的哪个结构发育而来的( )
在Rt△ABC中,∠C=90°,tanA=2,则sinB=( )