A．麦浪滚滚
B．铁水奔流
C．万里雪飘
D．灯光闪烁
答案：D
Xiao Pei said she ______ Hainan for 3 months.
A．has been in
B．had been in
C．had been to
D．had gone to
12岁儿童由饮水含氟量0．3ppm地区迁居饮水含氟量1．2ppm地区，氟牙症发生的可能性为（）
A.0
B.25％
C.50％
D.75％
E.100％
