The figure shows a schematic diagram of a weather system. A, B and C are located on the same latitude plain, and ①, ② and ③ represent some three links in the process of atmospheric heating.

(1) The temperature of the near-surface atmosphere decreases with the increase of altitude, because the direct heat source of the near-surface atmosphere is ground radiation, which is emitted from the ground to the atmosphere, so ③ is ground radiation.

(2) The cold air mass is located under the front because of its low temperature and high pressure density. When a cold air mass actively approaches a warm air mass, it is a cold front, and vice versa. The lower the temperature at the same height, the greater the pressure. When the frontal system is controlled by a single air mass, it is mostly sunny, and when it is controlled by the frontal surface, it is mostly rainy. The temperature on sunny days is higher than that on cloudy days because the atmosphere has a weak weakening effect on solar radiation. So, the answer is cold ABC ..

(3) The cold front was controlled by a single warm air mass before crossing the border, with clear weather, high temperature and low air pressure; There were strong winds and rainy (rainy and snowy) weather when crossing the border, but after crossing the border, the weather turned fine, the temperature dropped and the air pressure rose.

So the answer is:

(1) Ground ③(2) Cold ABC

(3) gale, rainy (rain and snow) weather? The weather turns fine, the temperature drops and the air pressure rises.