A:原子可以构成分子,也可以形成离子
B:原子种类由核内质子数决定,原子的化学性质主要由最外层电子数决定
C:它们都可以直接构成物质
D:原子中的原子核一定由质子和中子构成
当你在一个城市旅游时,你应选择下列哪一种地图作为导游图( )
A single-parent child should have the right to enjoy normal parental love from both just as his other peers, which some psychologists see as _____to their emotional well-being.
成语“趁火打劫”用来比喻乘人之危牟取私利。在第二次鸦片战争中干此勾当,强占中国大片领土的国家是( )