“给学生打高分以鼓励学习行为”是正强化的典型案例。
参考答案：对
The girl sometimes has difficulty（）what the teacher says in class.
A.understand
B.understanding
C.to understand
D.understood
瞳神紧小症首选的外治法是：（）
A.点激素眼药水
B.涂激素眼药膏
C.涂阿托品膏
D.热敷
E.耳尖放血
