题目

氯元素的相对原子质量为35.5，由23Na、35Cl、37Cl构成的11.7g氯化钠中，37Cl的质量为 A．1.75g             B．1.85 g         C．5.25 g          D．5.85g 答案：B If something is“dog-eat-dog”, it is a situation ________ people have to take care of themselves and look after their own interests． [　　] A．on which B．in which C．by which D．for which