现有五种光学组件如图A所示，对图B中的光路图，方框中可放入的组件为
A．2或4
B．1或5
C．1或3或5
D．2或3或4
答案：A
Any help from you will be greatly appreciated. P1ease give me a reply at your earliest .
A．interruption
B．instruction
C．consideration
D．convenience
有色丝的生产是通过向常规切片中添加（）来实现的。
A、色母粒切片
B、全消光切片
C、超有光切片
D、PBT切片
