By the time I was nine ,I ______hundreds of English words.

The fact has worried the people across the world ___________ the earth is becoming warmer and warmer these years.

Sarah is _______ a kind-hearted girl _______ she often helps people who are in trouble. [ ]

______ an Englishman, John is looking forwards ______the 2012 Olympic Games. [ ]

Is this the reason ______ at the meeting for his carelessness in his work?