【成考英語】2009年成人高考英語語法被動語態(tài)六：現(xiàn)在完成時的被動語態(tài)

六、現(xiàn)在完成時的被動語態(tài)
    承受者+have（復(fù)數(shù)主語）/has been done by+執(zhí)行者 （不明確可省略）
    E.g. 主動：Our School has finished many scientific researches.
    被動：Many scientific researches have been finished by our school.