下列仪器:①容量瓶,②蒸馏烧瓶,③漏斗,④燃烧匙,⑤天平,⑥分液漏斗,⑦胶头滴管,常用于混合物质分离的是[ ]
A.①③⑤
B.②④⑦
C.①②⑥
D.②③⑥
答案:D
-We missed you at this morning's meeting,Diana.
-________,but if I hadn't had to meet a friend,l would have been there. [ ]
A. Me,too
B. I'm sorry
C. Never mind
D. Thank you
医疗保险的理论基础是:对于每个人来说,其生病和受伤害是可预测的,而对于一个人群整体来说,则又是不可预测的。