He runs fast, here 'fast' is .....

Which one of the following is an adverb ? Which 'better' is an adverb? 'It's too soon to say if he'll survive' Here 'too' is a/an- The sun went down. The underlined word is used here as a/an: The dog was running behind. The underlined word is Down went the Titanic. The word 'down' is- The boy writes well. Here well is a/an 'Man cannot live alone'. The word 'alone' is used here as- Suddenly one of the wheels came off, এখানে off শব্দটি- Please look above. Here above is -