The english speaking contest,( )at 9:00am last F

题目

The english speaking contest,( )at 9:00am last F
The english speaking contest,( )at 9:00am last Friday ,was followed by an award ceremony.
A.starting
B.to start
为什么答案不是started?
如果没有逗号,是选started吧?

答案

不管有没有逗号都选A,这是现在分词作状语：
现在分词作状语 (表示动作发生的时间、原因、结果、条件、让步、方式或伴随情况,通常相当于一个状语从句或并列分句.一般说来,这种结构的逻辑主语就是句子的主语.)
1.All night long he lay awake,thinking of the problem.
2.The six blind men stood there begging for a meal.
3.Her husband died ten years ago,leaving her with three children to look after.
4.He sat in the armchair,reading a newspaper.
5.Having eaten his dinner,the boy rushed out.
6.Not knowing her address,I can't write to her.
7.Taking the path that leads out of the town,you will come to a lake.
8.Hearing their teacher's voice,the pupils stopped talking at once.
9.Their car was caught in a traffic jam,thus causing the delay.
10.Having lived with the girl for 5 years,we all know her very well.