it snowed heavily yesterday nobody in our class missed the lessonA. ThoughB. BecauseC.

问题补充：

it snowed heavily yesterday, nobody in our class missed the lesson．

A. Though

B. Because

C. Unless

D. Since

答案：

(答案→)A. Though

B. Because

C. Unless

D. Since

解析：本题的含义虽然昨天的雪下得很大，但是没有人缺课，表示的是让步，用though来引导，故本题选A。