我儿子今天没去上学，因为他在发烧。

My son is home from school today because he has a ___fever.

我朋友不得不留在家里照顾她弟弟，因为他发高烧了。

My friend had to stay home and take care of her younger brother when he had a high ___fever.

在流感季节，很多人发烧是很常见的。

During flu season, it's common for many people to run a ___fever.