1. unexpectedly
2. to one's surprise
3. go so far as to
4. actually.
Examples:
1. 她不但參加了競賽--而且居然獲勝了!
She not only entered the competition she actually won it!
2. 他是個懶鬼，他居然悄悄地溜走而把清除工作留給我們來做。
He's a slacker, he actually skipped off and left us to do the clearing away.
3. 他居然有臉要求賠償。
He had the gall to sue for damages.
4. 妳居然建議這樣的事，太可笑了。
It was absurd of you to suggest such a thing.
5. 妳太粗心了，居然連妳媽媽的生日也忘了。
It was thoughtless of you to forget your mother's birthday.
妳怎麽可以這樣做？:
How can you behave like this?
妳怎麽能這樣!:
How dare you!
怎麽能這樣!:
Surely not!
妳怎麽能這樣表現呢？
How can you take upon yourself to behave so?
妳怎麽能那樣待他呢？
How can you do that to him?
妳怎麽會那麽想呢？
How did you get that way?
妳怎麽能對我做這種事呢？
How can you do that to me?
妳怎麽能把這麽壹大筆債務忘掉呢？
How could you forget about such a large debt?
不可能，您怎麽能要求我們減價那麽多呢？
Impossible.How can you expect us to make a reduction to that extent?
妳怎麽能看著妳的兒子打小孩而不管呢？
How can you stand by and watch your son beat the younger child?
如果這是應該做的事，什麽能阻止妳這樣做呢？
If that's the right thing to do,what's to prevent you doing so?
面對受苦受難的人類，妳怎麽能毫無同情心呢？
How can you turn aside from suffering humanity?
對這種殘酷的事情，妳怎麽能袖手旁觀呢？
How can you stand by and allow such cruelty?