____(experiment) on several times ,this new type of machine will be put into mass production.在线等

问题描述:

____(experiment) on several times ,this new type of machine will be put into mass production.在线等

experiment 这个单词的中文是实验,名词又可做动词用,从后半句当中我们可以看到实验的对象是机器,所以前面的答案为过去分词 experimented ,表示被动的含义