The weather in Beijing on May 7th.

Question 1:D?

Question 2: B?

Question 3: A.

Test analysis:

Question 1: Sandstorm is the general name of sandstorm and sandstorm, and it

Question 1:D?

Question 2: B?

Question 3: A.

Test analysis:

Question 1: Sandstorm is the general name of sandstorm and sandstorm, and it is a weather phenomenon that mostly occurs in arid and semi-arid areas. It is formed by strong wind blowing soft dust on the dry surface, which leads to air turbidity and low visibility. So the primary pollutant is suspended particles, right? Dust storms are not necessarily related to polluted gases, and A, B and C are all wrong.

Question 2: From the perspective of ecological destruction, the cause of sandstorm is inseparable from sand dust, and the source of sand dust has little to do with the loss of sand dust. A is wrong. It is closely related to the increasingly serious land desertification. The larger the desertification area, the richer the dust source. Salinization does not necessarily form loose dust, nor is it the direct source of dust. C is wrong. The extinction of wild animals and plants is not the direct source of dust, and D is wrong.

Question 3: As a weather phenomenon, sandstorms can't be separated from strong winds, and cold fronts cross the border quickly, which is easy to produce strong winds and blow up dust on the surface, thus forming sandstorms. Warm front crossing, cyclone crossing and anticyclone crossing are less windy, and it is not easy to form sandstorm weather.