Нужно поставить say, tell или ask в нужную форму (согласование времён)
First, the headmaster said good morning. Then he _ us that police had been _ about hooliganism at school. The police _ that some pupils had been breaking windows. Several boys were _ if they knew anything, but of course they _ nothing. They were probably _ lies. The headmaster _ us all for information. He _ we must _ him the names of those involved. Well, I know who they were. But I cant _ him the secret. _ the truth isn't always easy, is it?