题目内容：
Based on the laser operation treatment of three patients。what can we infer from the passage?
A．Laser light treatment is safe and effective．
B．Laser light treatment is dangerous and ineffective
C．Laser light treatment still requires much more studies．
D．Government should encourage doctors to do research of laser light treatment on the human body．
参考答案：【答案仅供学习，请勿对照自行用药等】