Underline the correct word. e.g. They were happy so/because they passed

Underline the correct word. e.g. They were happy so/because they passed the test. We are late so/because we missed the bus. I was hungry, so/because I went to the fast food restaurant. She is wearing a coat so/because its cold today. He is tired so/because he didnt sleep. You have got a lot of homework, so/because you cant play basketball.