No one has yet succeeded in explaining the ___ of how life began.

. After so many days on the way, even Charles cheered up at the _____ of the food.

On your way to New York William will keep you ______if you don't want to be lonely.

The people from the south enjoy the________in the north during the winter because they have never seen snow before.

I’m told that you are going to Canada to have a three month further study. Don’t let such a good chance to improve your English _____ through your fingers.