Question

---- Why were you late for school again this morning?

---I was about to go shopping _________ it began to rain.

A. while     B. as

C. when     D. though

Answer

C

【解析】

试题分析：句意:-今天早上你为什么有迟到了？-我正要去购物这时开始下雨了。while 当……时候，引导时间状语从句；as 一边……一边……；when 当……时候；正在这时；though 虽然，尽管。这里使用的句型是be about to do sth. when…，正要做某事这时……。故选C。

考点：考查连词。