When all those present ___he began his lecture A,sit B set C seated Dwere seated

题目

When all those present ___he began his lecture A,sit B set C seated Dwere seated

答案

D were seated 坐下,位于,这是固定的搭配
sit 要跟down一起用
set是设置的意思
当所有出席的人坐下的时候,他开始了他演讲