It was nearly an hour ____the sleeping pill ______effect.
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.
Jane is one of the best students in her class who _____by their teacher.
Those who ____ in ____compositions, please hand them in this afternoon.