In the following passage some of the words have been left out. Read the passage carefully and select the correct answer for the given blank out of the four alternatives.
Passage:

Life is full of ______ types of experiences.Strange, in fact, are the ways of God.If a man is happy today, he may be ______ unhappy the very next day.Some ______ are pleasant and joyful while others are full of ______ and pain.If at one time a person finds himself on top of the world, at the ______ time he is depressed and downcast.