“drop ball”的概念、定义、翻译、参考文献-科学参考

单词	drop ball
释义	drop ball [`dräp ´bȯl] ^ENGINEERING A ball, weighing 3000-4000 pounds (1400- 1800 kilograms), dropped from a crane through about 20-33 feet (6-10 meters) onto oversize quarry stones left after blasting; this method is used to avoid secondary blasting.
随便看	line-balance converter line block line blow line brattice line broadening line-building-out network linecasting machine line characteristic distortion line circuit line clinometer line code line conditioning line conductor line-controlled blocking oscillator line conversion line copy line cord line-cord resistor line cut line defect line discipline line displacement line dot matrix line drilling line driver

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