在时间平均的基础上间断地实施奖励是下列哪种强化方法:()
A.固定间断
B.固定比率
C.变动间断
D.变动比率
参考答案:C
浇注过程应注意做到()。
A、参加浇注同学要平稳浇注,避免金属液飞溅
B、其他同学不准站在浇包近旁
C、浇注期间不准相互打闹
D、和正在浇注的同学或师傅进行谈话
—It was very crowded ()I went there last night. —I don't care whether it's crowded or not. I'd like to see it anyway.
A. though
B. because
C. when
D. since