— Can we make this plan a week later?

—No, we can't put off _______ it because the meeting is only two days from now.

标准状况下将 aL HCl气体溶于bmL水中，得到的盐酸溶液密度为c g•cm^﹣3，则该溶液中溶质的物质的量的浓度可表示为（　　）

注意：1). 词数80左右（短文的开头结尾已给出，不计入总词数）；

          2). 不得透露学校、姓名等任何个人信息，否则不予评分。

Dear Sandy,

     Welcome to my hometown!  

                                                                                                                                                                                             Yours,

                                                                                                                                                                                               Li Lei

能与氧化铜反应的固体单质是（  ）