therefore · as a result · so · the reason why

Catherine stayed indoors because it was raining.

She's grown out of her favorite dress, so her mother will have to make it over for her.

My television was broken down, so I had to get it repaired.

He said with a perplexed expression, "I've heard nothing, so I can't say anything."

I had an awful experience today, so I'm going to have a beer and go straight to bed.