消防控制室图形显示装置须（）内能够显示输入的火灾报警信号和反馈信号的状态信息。
A.10s
B.30s
C.50s
D.100s
参考答案：A
We tried to _______ his doubts and let him tell the truth.
A．replace
B．review
C．remove
D．rebuild
木牛流马的机关在什么部位？
