When you park on the street, you have to feed the meter all day long.
如果你在街边停车，你就得整天都付停车费。
The major work of this thesis is to design and make a good LPDA(log-periodic dipole antenna)as the feed of the ten-meter parabolic reflectors at the Yunnan Observatory.
文中所作的主要工作是为云南天文台十米抛物面设计、制造一付好的对数周期偶极子天线（LPDA）作馈源。
The invention also provides a dry feed and reaction system and a method for calibrating the solid mass flow meter.
本发明还提供了一种干法进料和反应的系统以及一种固体质量流量计的标定方法。
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