I’m a football fan. I was interested in everything _____is about the 2010 World Cup.

Is the girl in the red skirt your sister?—No. She is____ classmate.

Everyone must __________ the security check (安检) before getting on the plane at the airport.— Yes. It’s necessary to ensure the passengers’ safety.

I am looking after Tom today.He’s been in my house ______________ 8:00 this morning.

Please ask ___________. He may know which one is __________.