希腊文化是一种（）
A、求知理性文化
B、实践理性文化
C、实用理性文化
D、功利理性文化
参考答案：A
—Did you have any difficulty catching yesterday's lecture?
—No. The professor spoke very clearly to make his speech easy _____.[ ]
A. understood
B. understand
C. understanding
D. to understand
比例积分微分控制规律是指输出变量p与输入偏差e之间存在关系（）。
A.选项A
B.选项B
C.选项C
D.选项D
