三极管的三个工作区域分别是饱和区、放大区和（）。
参考答案：截止区
布鲁纳认为，知识结构可以用______几种表象形式来表现。
A．动作
B．图像
C．表格
D．符号
Sally likes , but Lily likes to .[ ]
A. swim; play volleyball
B. swimming; play volleyball
C. to swim; playing volleyball
D. swim; playing volleyball
