____ you ever _____to Yantai —Yes, three times.

It is a bad habit to ____ others’ homework.You should do ____homework by yourself.

Now there is a danger ________ the ground may fall in under the heavy traffic.

Peter， is ______ fork yours— No. I took it by ______ mistake.

This Sunday is an important day for my parents. We’ll celebrate it because they ________for twenty years.