Piya has slept only three hours. Which part of speech is the word only here?

'I will do it tomorrow'- এ বাক্যে Tomorrow কোন Parts of Speech? The day of my sister's marriage is drawing near'. The underlined word is a/an - The dog was running behind. The underlined word is Upoma came here late. Here late is- The up train is late. এখানে 'up' শব্দটি- 'Man cannot live alone'. The word 'alone' is used here as- Which one of the following is an adverb ? The bird flew high. Here, the word 'high' is a/an- The sun went down. The underlined word is used here as a/an: 'It's too soon to say if he'll survive' Here 'too' is a/an-