题目

如果“□×2ab＝2a2b”，那么“□”内应填的代数式是„„„„„„„„„„„„„„（                      ） A．ab                          B．2ab                        C．a                            D．2a 答案：C7．The waiter hardly has a day off，        ？（　　）A．hasn't heB．doesn't heC．will heD．does he