trial run的复数形式怎么拼写？

trial run的音标：trial run的英式发音音标为：['traiəl rʌn]trial run的美式发音音标为：['traɪəl rʌn]...

The machine failed on its trial run.但这部机器的试车失败了.Take the car for a trial run to see if you like it.试试那辆汽车,看看你是否满意.It was sort of like a trial run for the school camp.倒有几分像学校的野营的试行....

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