"This is the starting point. Unless there is an end, a real cessation from these activities, it will be difficult for any Palestinian negotiator to come back to the table.

VOA: standard.2009.04.09

These are difficult lines physically to read, and they may very well be the most painful lines in the entire poem from an emotional perspective.

从情感的角度看待整首诗，这几行比较难懂,读起来也比较费力。

耶鲁公开课 - 弥尔顿课程节选

the work doesn't seem to be that much more difficult from what's at other universities.

功课也没有比别的大学难很多。

对于赞助入学的看法 - SpeakingMax英语口语达人

"I think the most difficult thing will be to be separated from the people that I am used to, and leaving behind some of the habits - all our activity will be directed towards a certain goal."

VOA: standard.2010.06.02

One of the things that a lot of observers have been concerned about is the fact that there could be a change in tactics away from the kind of spectacular and very difficult operations to conduct to operations that could be launched in far greater numbers and might have less individual impact but which in the aggregate could sow a great deal of terror.

VOA: standard.2010.05.05