現(xiàn)在完成時(shí),主語(yǔ)+have/has+done例如：I have done my homework.我作業(yè)已經(jīng)做完了一般現(xiàn)在時(shí),主語(yǔ)+動(dòng)詞原型；特殊情況：主語(yǔ)是第三人稱單數(shù)時(shí),動(dòng)詞要變?yōu)槿龁涡问?比如have變?yōu)閔as現(xiàn)在進(jìn)行時(shí),主語(yǔ)+be+動(dòng)詞ing現(xiàn)在完成...I want to use the same equipments ____used in your factory last month. A as were B as wasC which wasD which我知道C和D是錯(cuò)的，但是A和B要怎么取選？為什么要用were 不能用was？首先是上個(gè)月的，所以要用過(guò)去是過(guò)去時(shí)態(tài)。但是人家是equipments啊，是復(fù)數(shù)，謂語(yǔ)動(dòng)詞怎么能用was單數(shù)呢。呵呵，這么解釋明白嗎？