Question

 (2011年陜西寶雞檢測(cè))Mary，I should tell you it is the third time that you________.

A．forgot to do                         B．forgot doing

C．have forgotten to do             D．had forgotten doing

Answer 1

解析：選C�？疾闀r(shí)態(tài)和非謂語(yǔ)動(dòng)詞�！癐t is(was)the＋序數(shù)詞＋time＋that從句”，表示“是某人第幾次做某事”。在此句型中，若前面為it is，則that從句用現(xiàn)在完成時(shí)；若前面為it was，則that從句用過去完成時(shí)。而forget to do sth.表示忘了應(yīng)去做某事，forget doing sth.表示忘了已做過某事。根據(jù)語(yǔ)意可知此題應(yīng)選C。