根据括号内所给的中文,写出单词的正确形式。
His back is __________(靠着) the wall. He has no way to run.
If you find yourself __________(不能) to sleep, you may do some reading.
Sam has few friends because he always ___________(拒绝) to help others.
There are many big companies and ____________(国际的) banks in New York.