教员想决定何时何地采用教具时，需要考虑的首要因素是什么？ What is the primary factor should be considered when using teaching aids?
A.把主题材料组织成框架或教学计划 The subject material should be organized into a frame or teaching plan
B.决定在课堂教学的哪一点或何时采用这些设备以便激发学员的学习兴趣 When should the AIDS be used to stimulate the learning interest
C.明确授课目的，并确定必须与学员交流的信息 Instructor should clear the teaching purpose
正确答案是C