英语题Someone_______intheclassroominthepast.Nobodyknowswhoheis
1.选择()Someone_______intheclassroominthepast.Nobodyknowswhoheis.
A.heardtosingB.washeardsingC.heardsingD.washeardtosing
2.填空Adictionaryisaveryh______tooltoyouwhenyoulearnlanguage(我觉得用helpful,对吗.)