America has been _(powerful) country in the world since World since World War 2.
我担心是否伤害了她的感情I was worried about _______ her feelings.
尽管有许多困难,我们还是设法完成任务_____________ there were many difficulties,we managed to finish the work.
-你介意帮我寄一封信吗?-当然不——Would you __________ this letter for me?— — ______.
你和我都是幽默随和的_________ you and ________ humorous and easy-going.