信源发出的信号共有4种状态，4种状态的发生概率各为1/4，信源传给信宿的信息熵是（）。
A.1
B.2
C.3
D.4
参考答案：B
In order to protect the environment, people are greatly encouraged to travel by public ____.[ ]
A. transport
B. service
C. means
D. traffic
为了防虫保色，常与泽泻同贮存的是（）
A.冬虫夏草
B.牡丹皮
C.肉桂
D.龙眼肉
E.大蒜
ly encouraged to travel by public 
____.[ ]