It's very difficult to demote somebody who has been filling in during maternity leave.

给替代歇产假的人降职是很难的。

《柯林斯英汉双解大词典》

For employers, filling vacancies within their business can be one of the most difficult obstacles to overcome.

对于雇主而言，填满他们企业中的职位空缺，可能是最难克服的障碍之一。

youdao

Policing can be a difficult and dangerous occupation, and the proliferation of laws and form-filling and what-not over the past decade have not made the job easier.

警察是个很有难度并且危险的职业，过去十年大量制定颁布的各项法律等并没有使警察的工作更容易。

youdao

Lizo: How difficult is it filling a part like Luna's?

BBC: Last Updated: Wednesday January 11 2006 09:25 GMT

Yet he made it sound as if it was no more difficult than pumping gas at a filling station.

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"Fueling is particularly difficult because the amount of money that would have to be put in to get hydrogen generated at filling stations is very costly and would require cooperation from everyone from the automaker to the government to the fueling station owners, " See said.

CNN: Hydrogen fuel-cell cars look to overtake electric autos