CFM56-5B发动机VBV系统是受（ ）控制，使用（ ）作为伺服压力。

Since nobody gave him any help, he ________ have done the research on his own.

Hitler set out to conquer all of Europe in the belief that the Germans were the master ________

The skyscraper stands out ______ the blue sky.

It is _______ impossible to find a perfect medical project in this part of the city.

By ______ Mr. White is a bus driver.

Let us get ______ this old barn. It is of no use to us.

In some countries men usually have to _______ when they reach the age of 55.

John wrote to a pen friend in England _______ for several years.

These envelopes are so small that letters have to be ____several times before they can be put inside.

In old times, property was usually handed _____ to the oldest son at death of his father.