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Many loocal camera shops, repair shops, and, of course, Canon, will clean your sensor.
The line on the photo looks like dirt, be sure to clean your lens. If there are marks or a hair on the rear of the lens, you could see this, on the front, its not likely you would see it that badly.
If you have a UV filter on the camera, remove it, make sure the lens is clean, front and rear, and try again without the filter. They can go bad.
If the smear is still there, I'd have Canon clean it, its unusually dirty, normally you have to view dust at 100% magnification.
The sensor would have to have had something wiped on it to make it that dirty.
