用括号内所给词的适当形式填空（每空不限一词）。
If you ____ (not be) careful enough in the exam, you will not get a good grade.
Our modern times need more and more ____ (hero) for us to learn from.
Good habits are good for the____ (develop) of us teenagers.
The 30th Olympic Games ____ (hold) in London this summer.
— Look! He is shouting at his mother.— Why is he so ____ (polite)?
The group of students are discussing the question____ (active) to come up with the answer.
The Three-D film Titanic is the____ (wonderful) film I have ever seen.
The OBIS doctor is training the local doctors how____ (deal) with the blindness.
Though my grandfather is in his ____ (seventy), he has got a QQ number.
Lei Feng devoted himself to____ (work) for the people all his life.
