A:成年人的正常体温是39℃
B:初中生的质量大约是50kg
C:普通自行车轮的半径约为1m
D:家用空调的功率为50W
It takes Janet about forty minutes her homework every evening.
如果|y﹣3|+|x﹣4|=0,那么的x﹣y值为( )