Re: Article The
1. After reaching the hospital, ... (you know this is not a complete sentence, right?). While in BrE if you are a patient in this type of facility, you are "in hospital" in all other uses, it requires an article. (And in the US, you are in the hospital if you are a patient.)
Originally Posted by gauri_agr
2. Before going to bed, I always brush my teeth. (Your sentence is simply not natural. There is no point in correcting it when no native speaker would say it.) We go to church, to school, to bed (and a few others) when the emphasis is on the activity - to worship, to learn, to sleep. If you say "to the church" you mean you are travelling to the buildling, but not for worship. If you say "to the school" it means to the building, but not to attend classes. If you say "to the bed" you are going to that piece of furniture, but not for the purpose of sleeping.
3. The doctor. It's a common noun, so it requires an article. Dr. Jones is a proper noun, so you don't have an article.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.