根据句意用括号中单词的适当形式填空，使句子的意思完整、正确。
The man in a white shirt is in his ________．(fifty)
I doubt whether it is worth ________ so much time on homework．(spend)
After hard work, he ________ in getting a scholarship．(success)
Red may help when you are having difficulty making a ______．(decide)
As a good doctor, you should not be too ________．(impatient)