1~3岁儿童每人氟的适宜和安全摄入量(mg/d)是()
A.0.1~0.4
B.0.5~1.5
C.1.6~2.6
D.2.7~3.7
E.3.8~4.8
参考答案:B
— Tom has been to Beijing before.
— _______. [ ]
A. So has he
B. So he has
C. So is he
D. So he is
新闻评论标题的主要功能,不包括()
A.概括论题的范围
B.揭示中心论点
C.激发受众热情
D.表明作者态度