二次信号电缆与一次电缆同沟敷设时二次电缆需采用（）.
A.阻燃电缆
B.屏蔽电缆
C.铜芯电缆
D.铠装电缆
参考答案：B
某甲苯塔进料流量为150t/h，塔顶采出流量为49t/h，塔底采出流量为99t/h，请计算该塔的物料平衡率。
The headmaster could not go to the meeting; therefore, Mr. Smith _______ him.
A．ranked
B．represented
C．took the place
D．modelled
