A light signal consisting of three flashes means ().
A. I am in doubt as to your actions
B. My engines are full speed astern
C. I desire to overtake you
D. I am operating astern propulsio
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道岔防跳限位装置与斥离尖轨(标准开口)间隙应为()mm。
Photoshop7.0软件所支持的、本身最主要的格式为()。
A. BMP
B. PSD
CMYK
D. EPS