奥运会开幕式总让来宾们印象深刻.(impression)
The Opening Ceremony of Olympic Games always leaves deep impression on the guests.
上交考卷之前,请尽量仔细检查.(as)
Please check the exam papers as carefully as possile before turning them in.
机会难得,你不妨充分利用它.（may）
Such opportunities may not come again.You'd better take full advantage of them.
如果我们带着坚定的意志去工作,无论困难有多大,我们都能克服.（however）
However difficult it may be,we can overcome it with our determination.