The boy insistedthis;given

A special team was sent to Shandong Province to look into the cause of the train accident, and the investigation suggested that high speed______.

What can I do for you, sir?-No, I only want to speak to the person ________.[ ]

There are ______ students in this school.

Mistakes don’t just happen; they occur for a reason. Find out the reason, and then make the mistake becomes _____. [ ]