I hate to trouble you, but could I use your phone?

我不愿麻烦你，但我能用一下你的电话吗？

《牛津词典》

Sorry to bother you, but could I speak to you for a moment?

不好意思打搅你，我能不能跟你说几句话？

《牛津词典》

He looked up at the buildings opposite, but could see no open window.

他抬头看了看对面那些楼，但看不见一扇开着的窗户。

《柯林斯英汉双解大词典》

Her teachers said the little girl knew all the rules but could not seem to follow them.

VOA: special.2009.07.31

Question: But could the patient have ? still been alive, nevertheless?

问题，但即使如此,这个病人当时可能还是活的，对吗？

耶鲁公开课 - 死亡课程节选

So, it's more effective because it's a live virus but it's a little bit more concerning because it's a live virus as well, in that you trust that it's attenuated but could it convert back to a virulent form or a form that caused a disease.

因此,口服疫苗更加有效,因为它是活性病毒,但又是因为这一点,人们也存有更多顾虑,当它处于减毒状态时你会信任它,但是它会不会转变回,强毒壮态或者致病状态呢

耶鲁公开课 - 生物医学工程探索课程节选

It has been run as a small luxury hotel, but could easily be a private residence.

FORBES: Provencal Retreat

Currently it only works for soccer but could soon come to other sports as well.

FORBES: With $10.7M More, Luminate Launches App Store For Images

Both teams created openings late on but could do nothing to break the deadlock.

BBC: Aston Villa 0-0 Man Utd