题目

下列计算中，正确的是（ ） A . 2a2+3a＝5a3 B . 2a2•3a＝5a3 C . 2a2÷3a＝ a D . （2a2）3＝8a5 答案：CIn England, people usually start a conversation with the topic about the weather. So when you hear someone say “ ________” you should reply “Yes, I hope so.”A.You look nice today.B.It’s raining again, but it will be fine later.C.What a sunny day!