A:Mg2+、H+、C1-、OH-
B:Na+、Ba2+、CO、NO
C:Na+、H+、Cl-、CO
D:K+、Cu2+、NO、SO、
____
(从左到右依次填写)
Jane is the only one of the students who ________ a little Chinese and is one of my friends who ________ studying in China now.
下面某同学绘制的关于中国现代外交的年代尺,仔细阅读,回答问题。