A：北寒带变大2度
B：热带变大2度
C：北温带变大4度
D：南寒带缩小4度
成分（mmol/L）
Na+
K+
Ca2+
Mg2+
Cl﹣
有机酸
蛋白质
①
142
5.0
2.5
1.5
103.3
6.0
16.0
②
147
4.0
1.25
1.0
114.0
7.5
③
10
14.0
10.35
25
﹣
47
—The children in rural areas have few books to read. Let's ______ some books to them.—Great, it is a good idea.
