在填写DS160时,step one 中说:As part of the electronic submission of your application, you will be asked to provide an electronic copy of a photo of the applicant. The photo must meet requirements for photo submission. If you wish to test your photo prior to beginning the application, you may use the test photo button below. 这是不是说必须提供电子照片?我只有纸版的,也不知道扫描一下能不能传上去?