短语词组短語Begin seriously to do homework 著手認真做家庭作業begin to do sth 開始做某事;開始去做某事;起頭做某事;開始做begin to do something 開始做某事begin to do sth purposefully 口〉全力以赴begin to do begin doing 開始做某事begin to do -began to do 開始做某事 返回 begin to do