The experiment shows that proper amounts of physical exercise, if _______ regularly, can make a
difference to our health.

_____with the size of the whole earth, the biggest ocean does not seem big at all.

Once _____ a difficult and even dangerous place _____,Vietnam is now a friendly destination that welcomes
visitors from all over the world.

She was ____ to study medicine to help the poor when she was a middle-school student.

I refused his request, _________ that it was impossible to do it.  

用limit 的短语或其适当形式完成句子。
1. One's energy is ____
2. ____  ( 没有止境) what you can do if you try.
3) We must  ____ our weekly expenditure ____ ten pounds.
4)Only a ____   number of places are available.

The girl _____ Susan, who often helps other people, _____ Lei Feng in this university.

Michael put up a picture of Yao Ming beside the bed to keep himself ________ of his own dreams.

_______ an important role in a new movie, Andy has got a chance to become famous.