用所给单词的适当形式填空。 1. He is one of the top ___ (chef) in the restaurant. 2. I think that paper is the most useful ___ (invent). 3. 1 wish all of you a____ (please) journey. 4. We should take an____ (act) part in all kinds of outdoor activities. 5. We learn history in school and may know about something before a few __ (century).