CR成像过程中，IP将X线转化为
A．电信号B．可见光C．数字信号D．高能射线E．银离子
参考答案：B
________they visited the Science Museum, they showed great interest in everything they saw. [ ]
A. The first time
B. For the first time
C. At first
D. At the first time
综合布线系统中水平子系统线缆的长度限制为（）。
A.180m
B.120m
C.90m
D.60m
