已知∠A=38°24'，则∠A的余角的大小是______．
根据定义∠A的余角度数是90°-38°24'=51°36′．
故答案为：51°36′．
---How did you work out the difficult chemistry problem?
--- I worked it out by ________.
A．working with a group
B．think very hard
C．ask the teacher for help
D．doing oneself
奥地利的GDP总量比比利时的GDP总量少（）。
A．5%
B．16.3%
C．19.4%
D．22.5%
