A lot of studends are having all kinds of spots on the spots field. A football game is going on just now____Class 3 and class 4. We don’t know which team will ______. Look at those people over there! Some students of class 1 are practicing  the _____jump. One of them is the best high jumper in the school. He practices hard every day. Many people think he will ____the school record（记录) in the sports meet next spring. Not far away from them，some girls are preparing for a race. They _____have a 600-meter race in ten minutes. Now in the corner of the field, you can see another group of students. Their teacher is telling them __to throw discus(铁饼).   In schools, _____students love sports now.  Sports help people to keep _____. They also help people to live happily. And____doing sports on the sports field , many people will  ______good friends, too. Do you think so?

在燃油锅炉中，（）是基础。

A.蒸发

B.燃烧

C.传热