氟牙症多见于恒牙,乳牙者甚少,是因为()
A.胎盘屏障
B.8岁以后生活在高氟区
C.刷牙时吞服含氟牙膏
D.氟骨症的表现
E.以上都不对
参考答案:A
—What a big storm last night!
—Yes. I was doing my homework. Suddenly, all the lights in my house _______.
A.went off
B.turned off
C.took off
D.got off
阿尔勒位于法国哪个地区?()
A、波尔多
B、勃艮第
C、普罗旺斯
D、干邑