the, a/an or no article

My mom exercises five times _____ week.

_____ man was hit by a car when he was crossing the streets. The man is a construction worker that was on his way to work.

Davi is _____ student.

I can run ten kilometers _____ hour.

In _____ U.S., _____ second day of the week is Monday.

Last year I went to _____ Galápagos Islands.

Canada is one of _____ coldest countries in the world.

Vitor is _____ tennis player.

_____ men are usually taller than women.

I bought the tickets for the concert on _____ Internet.

_____ U.K. comprises four countries: Emgland, Scotland, Northern Ireland and Wales.