题目

Se是人体必需微量元素，下列关于和的说法正确的是 （   ） A．和互为同素异形体          B．和都含有34个质子和中子 C．和分别含有44和46个质子 D．和互为同位素 答案：D Linda, with her parents, the Yellow Mountain and they will be back tomorrow?A. has gone to B. have gone to C.has been to D. have been to