— I want to speak to Tom.

— He isn't here. _____?

A. Can I take a message?

B. Would you like to leave a message?

C. Would you please give a message?

D. What is your name?

已知对角线规则为：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

A．BeO为两性氧化物

B．Be(OH)₂难溶于水

C．H₃BO₃是难溶于水的弱酸

D．B₂O₃既能溶于强酸又能溶于强碱