At such junctures he always had an impulse to leave.在这样的紧要关头,他总有要离开的冲动.At such junctures he always had an impulse to leave; it was needed on special occasions.在那时他总有要离开的冲动, 在紧急时刻她站了出来....
专业学科充满陷阱，专套粗心大意的人。Specialist subjects are full of pitfalls for the unwary.工程学和工艺学互不相同，也有别于自然学科。Engineering and technology are disciplines distinct from one another and from science.这本书基本上会让那些不熟悉该学科的人对其有个初步了解。The book is ...