Read the schematic diagram of common weather system. Complete the question 10- 1 1. The weather system related to the dry weather in the Yangtze River valley in summer is () A.AB.BC.CD 。

A and A are cyclones, and the dry weather in the Yangtze River basin in summer is influenced by subtropical high, which does not conform to the meaning of the question.

B and B are warm fronts, and the dry weather in the Yangtze River basin in summer is influenced by subtropical high, which does not conform to the meaning of the question.

C and C are anticyclones, and the summer dry weather in the Yangtze River basin is formed by the influence of subtropical high, so it is correct;

D and D are cold fronts, and the dry weather in the Yangtze River basin in summer is caused by subtropical high.

So choose: C.