I often see my mother __________ chess with my father after supper.

－Have you seen Mr. Black these days, Jack?－Yes, I met him when I ________ in the street yesterday.

It's very important ______healthy food.

---I often chat with my friends on the Internet.---You are so smart! Will you please tell me ________?

My family consider        a computer, which is considered       a great help in our work and study.