Weared weather

1. According to the sign of the front, this is a warm front. The first air pressure is 990 hectopascals, and the second air pressure is 1? 0 10 hectopascals, where a is low pressure and b is high pressure. Frontal weather usually forms rainy weather, so it is often combined with cyclone to form frontal cyclone. Cyclone is the center of low pressure, so it is correct;

B, the front will generally form rainy weather, so it is often combined with cyclone to form frontal cyclone. Cyclone is the center of low pressure and B is the center of high pressure, which does not conform to the meaning of the question;

C, according to the symbol of the front, it is a warm front. The first air pressure is 990 hectopascals, and the second air pressure is 1? 0 10 hectopascals, where a is low pressure. B is high pressure. Frontal weather usually forms rainy weather, so it is often combined with cyclone to form frontal cyclone. Cyclone is the center of low pressure, and the isobar is curved, which will close together into a center, which does not conform to the meaning of the question.

D, according to the sign of the front, it is a warm front. The first air pressure is 990 hectopascals, and the second air pressure is 1? 0 10 hectopascals, where a is low pressure and b is high pressure. Frontal weather usually forms rainy weather, so it is often combined with cyclone to form frontal cyclone. Cyclone is the center of low pressure, and the isobar is curved, which will close together into a center, which does not conform to the meaning of the question.

So choose: a.