The more one is ______ the English-speaking environment, the better he or she will learn the language.
What is even more important is______ the earth cooled down, water began to appear on its surface.
His idea was such a good one ______ we all agreed to use it.
Although the causes of cancer_____, we do not yet have any practical way to prevent it.
With just four years _______, the Brazil Olympic organizers have promised to deliver an equally inspirational ceremony.
We are so sorry for that.We'll try to determine exactly _________ went wrong that evening.