Geography is related to the weather ~ urgent, choose a topic+big topic ~

8-9.d； D. If the weather activity on the vertical plane in the figure is cold front crossing, then M is sunny and N is rainy, and it can also be concluded that M is higher than N, then the weather situation in the figure is that the center is high and M is at the ridge of high pressure, and the wind blowing from the center of high pressure turns from northwest to northeast under the action of the gravity of the earth.

10-11.a * persona & lty, due to the lack of some conditions in the figure, the default top is north, and then the following judgment is made: firstly, from the prompt, we can know that abcd air pressure is 1006, while abcd is 50, 100 respectively. B<c<d, we can know that the weather situation is high in the center and the wind direction at M is southeast wind. If this high pressure is located in the Pacific Ocean of 25-30 N, only summer can be judged, and the D option is excluded. Of course, I personally think there is something wrong with the setting of this question. If we only look at the answers, I think BD should be more reasonable. How can I expect the questioner to reply me directly? ...

1 1. As can be seen from the figure, it describes the situation when the cold front passes through the border. Zhengzhou and Xi 'an are two situations before and after the cold front crosses the border. Zhengzhou is self-evident: rain, low pressure; Xi 'an: It's sunny and the air pressure is rising. In addition, if you think the data in this picture is correct, you can use it as an example of cold front crossing to study the weather before and after cold front crossing. This is a dynamic situation, so you should add some ideas. For example, after the cold front passes through Zhengzhou, Xi 'an may face a local situation. Depending on the topic, this exercise should be about air pressure. Mastering a graphic is always more vivid and easier to understand than words. Of course, I suggest you ask your teacher first to see if this figure is credible.