When the retina reflects the beams, what occurs？
A. Patients have trouble seeing.
B. The ability to focus is gone.
C. No correction is needed.
D. The lens bends the light beams.
查看答案
Why isnt it important what McKay sees in the machine？
A. He doesn"t like the machine.
B. An eye chart is better.
C. It"s what the machine sees in him that is important.
D. The prototype doesn"t work very well.
What do the thousands of light beams measure？
A. The focusing accuracy of the lens of the eye.
B. Eye color and vision.
C. Where the beams travel.
D. The reflection of the retina.
微信支付 
支付宝支付