题干
— What a sunny day!
— Yes. You'd better take a sun umbrella to protect yourself _______ the sunshine.
A：of
B：from
C：under
D：to
答案(点此获取答案解析）
B
— What a sunny day!
— Yes. You'd better take a sun umbrella to protect yourself _______ the sunshine.
A：of
B：from
C：under
D：to
表示的粒子：S；④两个铁离子：2Fe3+；⑤导电、导热性最好的金属：Ag；⑥+2价的镁元素：Mg2+．其中正确的有（ ）
，则
等于
