Could you please tell me what happened _____? — OkayI know you are really pressed for time right now[ ]

There is something wrong with my watch, will you ? —Let e see.

We laugh at jokes, but seldom __________ about how they work.

Have you ever _____ Mudanjiang to see the Jingbo Lake—Yes, I have.

I often see light in that empty house. Do you think I ____ report it to the police? [ ]