It is very kind _______ you to help me with my housework. It is hard _____me to do all the work.
Neither Tom nor Jack and I ____ his students.
The rich ____ not always happy.
I, who____ your friend, will try my best to help you with your English.
The United States of America _____one of the most developed countries in the world.
The whole class _____the teacher attentively.