大多数偏头痛在儿童和青年期发病，晚发型偏头痛可在45岁以后发病。()
参考答案：对
裂纹敏感性
In reading a weather map, closely spaced pressure gradient lines would indicate（）.
A.high winds
B.high overcast clouds
C.calm or light winds
D.fog or steady rain
