饮水氟浓度超过多少以上就可能引起氟骨症()
A.1m/L
B.2m/L
C.3m/L
D.6m/L
E.10m/L
参考答案:C
Can you tell me how old ________? [ ]
A. is the girl
B. the girl is
C. are you
D. are they
有连丝现象的中药是()
A.连翘
B.杜仲
C.菟丝子
D.夏枯草
E.银柴胡