从事遗传病诊断、产前诊断的医疗、保健机构和人员，须经（）人民政府卫生行政部门许可。
A、省、自治区、直辖市
B、县级
C、州（市）级
D、乡镇
参考答案：A
当建筑物设进车道时，机动车通行的最大坡度为( )。
A．8%
B．6%
C．4%
D．3%
Frank is very lonely, he has few friends, _____? [ ]
A. does he
B. doesn't he
C. is he
