每句有一处错误，请按以下要求改错：错误：把某词改为某词．写为：某词---某词．例如：was--were增加：在某词后加某词．写为：某词后加某词．例如：by后加the删除：去掉多余的词．写为

　　每句有一处错误，请按以下要求改错：

　　错误：把某词改为某词．写为：某词---某词．例如：was--were

　　增加：在某词后加某词．写为：某词后加某词．例如：by后加the

　　删除：去掉多余的词．写为：去掉某词．例如：去掉a

　　71．Comparingwith2005，thepriceofgrainwasincreasedby50%．

　　72．Ratherthandrivinghimself，healwayspreferstorideabicycle．

　　73．Itwilldependonifthisproblemcanbesolved．

　　74．Ihavesomedoubtthattheycancompletethetaskontime．

　　75．Thisteacheroftenhelpedmemaybebecausehefeltitselfhisdutytodoso．

　　76．Someofthetalltreesweremeasuredover90metres．

　　77．It'sverylatetotakeanybuses，sowehavetowalkhome．

　　78．AslongasIknow，theyliveinthesameneighbourhood．

　　79．TheorganizationisinchargeofDavidwhoisverycapableofmanagingit．

　　80．Wetookturntodrivewhengoingtotheseaside．