rough sledding

同根派生

Many of these proposals could encounter rough sledding.
这些提议中有很多会碰到不利情况。
Jane had rough sledding in her math course because she was poorly prepared.
简的数学课学得很吃力，因为她的基础很差。
Investigators have discovered many drugs that cure artificially induced cancers in rodents, but when the substances move into human trials, they usually have rough sledding.
研究人员已经发现到，许多药物可以治愈齧齿动物身上人为诱发的癌症，可是一旦把这些药物拿来进行人体试验，之后的路就变得非常的崎岖。
The man attached a strong rope to his sled.
那人将一条结实的绳子系在他的雪撬上。
This rough track will soon be a metalled road.
这条坑坑洼洼的路不久就要铺上碎石了。