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short answer: yes.

google "install windows usb" or something similar and you'll find tons of ways you can get the job done.
 
Support for the Windows 7 ISO installer
Install Windows with an installation disc you provide or, on Mac computers that do not have an optical drive, with a USB flash drive that contains a Windows 7 ISO image downloaded from Microsoft. The Boot Camp Assistant will offer to create this image on supported computers.

http://support.apple.com/kb/HT4818
 
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