接触网设计最高温度一般采用（）°
A.40
B.45
C.50
D.55
参考答案：A
商店购进一批复读机，每台进价为98元，售价为128元，售完后盈利3600元，这批复读机共有多少台？
. The silence of the library ___ only by the sound of pages being turned over.
A．has been broken
B．breaks
C．broke
D．was broken
