A:﹣2m2
B:0
C:﹣1
D:﹣2
老师买回一些学习用品(数量相同).老师付给营业员100元,找回28元,请问找回的钱对不对,你是怎么判断出来的?
—What's your idea about family education?
— kids learn to be independent, it is for their future.
蜡块在加热时,会从____变成____,冷却时会从____变成____。