其穴定取方法是：
A．仰卧位取穴
B．俯卧位取穴
C．立位取穴
D．侧卧抱膝取穴
E．坐位取穴
参考答案：D
屈光手术的视光学原则包括（）
A.合理欠矫原则
B.双眼平衡原则
C.最佳矫正原则
D.无损害原则
E.无痛原则
The ______ has several major components, including the system kernel, a memory management system, the file system manager, device drivers, and the system libraries.
A．application
B．information system
C．operating system
D．iterative
