How does a pinhole projector work?

If<br/>a light passes through a small pinhole, and incident on a screen.<br/>What will be observed on the screen? A: A<br/>sharp bright point of the width equal to width the pinhole B: A<br/>bright point of the width equal to width the pinhole but of less<br/>intensity C: A<br/>bright ring at the center surrounded by alternate dark and bright<br/>rings D: A<br/>diffused bright point

获取一张图片可以通过软件上面哪几个参数调节图像亮度（） A: laser B: master gain C: pinhole D: frame side

If the abnormality in the visual acuity is improved with pinhole test then most likely cause of decrease visual acuity is A: cataract B: Glaucoma C: Corneal opacity D: refractive error E: all of the above

关于激光扫描共聚焦显微镜与宽场荧光显微镜，描述正确的是（ ）。 A: 激光扫描共聚焦显微镜都是倒置显微镜，荧光显微镜都正置显微镜 B: 激光扫描共聚焦显微镜与宽场荧光显微镜成像原理是一样的 C: 激光扫描共聚焦显微镜有pinhole，荧光显微镜没有pinhole D: 使用激光扫描共聚焦显微镜核宽场荧光显微镜时可以设定曝光时间