名词
中文翻译：投球直径规
同义词：
['投球器，投球尺例句：1. The pitcher used to measure the length of the ball when it was thrown.（投球器用来测量球被扔出去的长度。）']
例句：
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1. The pitcher used to measure the length of the ball when it was thrown.
投球器用来测量球被扔出去的长度。
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2. This pitcher is a great tool for measuring the size of the ball during the game.
这个投球器是比赛期间测量球大小的理想工具。
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3. The pitcher has been in use for many years and is still working well.
这个投球器已经使用了多年并且仍然工作得很好。