Acid rain is the influence of human activities on the weather.

Test answer: b test analysis: test analysis: the formation of acid rain is caused by human emission of acid gas into the atmosphere; The appearance of ozone hole is caused by human emission of chlorofluorocarbons into the atmosphere; The occurrence of sandstorm weather is caused by strong winds and human activities, and has nothing to do with solar activities; The phenomenon of "magnetic storm" is caused by the interference of solar activity on the earth's magnetic field. So choose B. Test center: Solar Activity Comments: This question examines the influence of solar activity, and the test questions are less difficult. The key to solving the problem is to remember the influence of solar activity.