问题补充：
单选题AlthoughJamesCookthefirstwesternertohavediscoveredAustralia,NewZealandandHawaii,histravelsledtothecreationofmoreaccurateandreliablemapsforvastpartsoftheworld.A.isn’tB.wasn’tC.must have beenD.may not have been
答案：
D解析从to have discovered及 led 可知此处表过去，从句意上看应为“过去可能不是”，故选D。
