单项选择题
A.850hpaB.700hpaC.500hpaD.300hpa
A.1000hpa-925hpa;大洋上B.925hpa-850hpa;大洋上C.850hpa-700hpa;大洋上D.700hpa-500hpa;大洋上
A.8天左右B.4天左右C.5天左右D.2天左右