帮我看看这个问题，Nowtherearetwofilesnamedgood.txtandbad.txtinthesub-directorytest,howcanyouexchange
帮我看看这个问题，
Now there are two files named good.txt and bad.txt in the sub-directory test, how can you exchange the names of the two files?
（交换两个文件的名字）
[解决办法]
mv good.txt tmp11111111111.txt
mv bad.txt good.txt
mv tmp11111111111.txt bad.txt