题目

——What did your granddaughter say just now?——She wondered ___________. A . what time was it B . whether the book was written by Mark Twain C . how could she use the MP4 D . when she will have a final test 答案：B下列叙述中，正确的是( )A.二氧化碳分子是由一个碳原子和两个氧原子构成的B.元素的化学性质主要取决于原子的核电荷数C.分子和原子的本质区别是分子可分，原子不可分D.镁离子和氧离子的核外电子层结构完全相同