数学课上,王老师先在黑板上写了四行字:(1)上午和下午共下雨7次;(2)有5天下午没有下雨;(3)有6天上午没有下雨;(4)下午下雨的那几天,上午都没有下雨。然后,他告诉大家:“这是学校气象兴趣小组在一段时间里观察天气得出的结果。根据这个统计结果,同学们来计算一下,气象兴趣小组观察的这段时间共有多少天?其中全天都没有下雨 In math class, Wang wrote the four lines first on the blackboard: (1) 7 times in the morning and afternoon; (2) 5 days in the afternoon without rain; (3) 6 days in the morning without rain; (4) In the afternoon when it rained, it did not rain in the morning. Then, he told everyone: ”This is the result of observing the weather over a period of time by the School Weather Panel, and based on this statistical result, students calculate how many days the weather interest group observes during this period It’s raining