1. To his delight,   he took the first place in the previous exam and made a good impression on his teachers and classmates.  His parents were also delighted to know about it. (delight)

2. The representative is admirable,   who is greedy for knowledge.  People admire him for his great contribution to ecology. (admire)

3. Tom is an assistant teacher in the college,  who is optimistic. He constantly assists his students with their problems and gives assistance to any student in need. (assist)

4. He is a professional typist working in a press and was at the very top of his profession.  Now he often guides new colleagues to type fast. (profession)