The weather sign of frost is: (

Test and analysis: On the weather forecast chart, we can see some symbols, which are used to represent the weather conditions. Only by mastering the meanings of these symbols can we understand the weather forecast. A is a thunderstorm, B is a typhoon, C is a sandstorm and D is frost. So choose option d in this question.

Comments: On the one hand, this topic examines the understanding of weather symbols, on the other hand, it also needs to understand the relationship between climate and human production and life, a basic topic. According to the understanding of weather symbols, judge the influence of different weather on production and life, and judge whether the corresponding relationship is correct.