﹣﹣﹣Why were you late for school this morning,Tom?
﹣﹣﹣I was about to go to school _________ it began to rain.( )
A.sinceB.whileC.asD.when
Sue told me that she ____________ shopping with her sister the next day.
By the end of last week, she______in the west of China for two months helping the homeless children.
Ken was so busy when we saw him, because he _______ a speech the next day.
--- What did he tell you just now?--- He said that ____________ tomorrow morning.
By the time Dave reached the small boat, a thick white fog _______ over the surface of the water.