题干
__________ a stay did you have in mind?
A：How old
B：How long
C：How much
D：How soon
答案(点此获取答案解析）
B
__________ a stay did you have in mind?
A：How old
B：How long
C：How much
D：How soon
为：沿周期表中金属与非金属分界线方向对角的两主族元素性质相似，如Li与Mg,Be与Al，B和Si相似，则下列叙述中不正确的是