at its best and worst这个短语是什么意思?

at its best and worst这个短语是什么意思? wasteful at best and cruel at worst The best and the worst, Sue is both the 50th best and 50th worst student at school,h 英语翻译Sue is both the 50th best and the 50th worst studend at at one's worst是什么意思 at worst best 5 and worst 5 comedy movies in USA? Hope for the best and prepare foe the worst. The best and the worst jobs的阅读理解 It was the best of times and the worst of the best and worst英语作文,急用啊!