交换机从阻塞状态到转发状态所需要经历的时间为（）
A、35
B、45
C、50
D、55
E、10
参考答案：B
It took ability to get the job. It took luck, too.
A．rather than
B．other than
C．more than
D．less than
胆总管内压力上升到哪个值时，肝脏分泌胆汁受到抑制
A．0.98 kPaB．1.96 kPaC．2.94 kPaD．392 kPaE．4.90 kPa
