题目

   Winter is the time of year when people feel very blessed. This isn't because people feel thankful for the cold weather, nor because the important festivals---Christmas or Spring Festival---offer an excuse to celebrate. In fact, “Bless you!” is a common response if someone sneezes, a symptom (症状）of catching a cold or the flu.    Colds and the flu are the most common illnesses of autumn and winter as the weather gets colder. Viruses cause them. If you get one you will feel annoyed, but it is not usually serious. The flu is spread from person to person when we come into 一个三角形的底是2.5厘米，面积是10平方厘米，它的高是x厘米，列方程是A.2.5x=10B.2.5x×2=10C.2.5x÷2=10