When I got to school, the teacher had started()the test papershand outhanded out to hand outto handing out
问题描述：
When I got to school, the teacher had started()the test papers
hand out
handed out
to hand out
to handing out
答
handed out
答
to hand out
答
to hand out
start to do sth 是固定搭配,意思是 开始做某事
When I got to school,the teacher had started to hand out the test papers
我一到学校,老师已经开始分发试卷了.