问个英语问题 The ratio of the work done by the machine

问个英语问题 The ratio of the work done by the machine The ratio of the work done by the machine ( C )the work done most of the farm work is done by machine in China today. the work is done by if one pays by the amount of work done and not by the hour.d the amount of work done by the gas system in increasing the 翻译：　The machine can do the work of three people The machine suddenly stopped(work)----because of the power o work done to the system和work done by the system的区别 The work done by the man was difficult.The man did the work Find the ratio of the following: He insisted that the idea evolve out of work done by British