-What colour is the pencil?
-It's yellow.
A:
B:
“类推”是学习化学的常用方法,下列推理正确的是( )
①10﹣3=0.0001; ②(0.0001)0=1; ③3a﹣2= 13a2 ; ④(﹣2)3÷(﹣2)5=﹣2﹣2.