It is also true that it is difficult to think of a single such system that has not, for better or worse, been substantially modified by human culture.

同样，很难想象一个这样的系统：不管是好是坏，都没有经过人类文化的实质性修改。

youdao

You know, I think it's great also in a way because I've been through difficult times and I've worked really hard.

我也曾经历过困难时期，也曾付出极大的努力，但我坚持了下来，我从不气馁。

youdao

It's true that we have been leading a difficult life, for we need not only to be under various external pressures, but also to be in the face of internal perplexities.

我们确实活得艰难，一要承受种种外部的压力，更要面对自己内心的困惑。

youdao

just to make it more difficult for them to operate. Shaaf also says that the government has been using whatever laws it can to shut down organizations dedicated to civic activism.

VOA: standard.2009.08.04

Her personal life has also clearly been difficult over the past few years.

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"This fault has proved a complex one to resolve and our engineers' efforts have also been hampered by the difficult weather conditions, " it said in a statement.

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Management have also said that it has been difficult to maintain productivity when at times up to 1, 000 workers are brought in on short-term contracts.

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