worked their arduous way up the mining valley; a grueling campaign; hard labor; heavy work; heavy going; spent many laborious hours on the project; set a punishing pace.

• 以费劲的方式建设着他们的矿谷；紧张的战役；辛苦的劳动；繁重的工作；艰难的进展；在这个计划上花费了许多令人筋疲力尽的时间；按照累人的速度。