49.Increasing problems of all kinds with fossil fuel power plants are turning power and utility companiesmoreandmore tOtheuseOfnuclearpoweredelectricgeneratingplants.
矿物燃料发电厂所产生的问题日益增多,这就促使电力公司和公用事业公司越来越倾向于采用核动力发电厂。(problem...with,“在……方面产生的问题”,with有表示“范围”。)
50.Ever since,people have had difficulty in deciding whether the hovercraft should be ranged among ships,planes,or land vehicles—for it is something in between a boat and anaircraft.
从那以后,人们感到很难确定把这种气垫船归为哪一类:船、飞机还是车辆,因为它是一种介于船与飞机之间的交通工具。(in between,“介于两者之间”,作定语修饰something。)
51.The electric resistance of a wire is the ratio of the potential difference between it stwo ends to the current in thewire.
导线的电阻等于该导线两端之间的电位差与导线中电流的比值。(tothecurrent..。是ratio要求的。the ratio of A to B,“A与B之比”。)
52.Pollution is caused either by man’s release of completely new and often artificial substances into the environment,or by releasing greatly increased amounts of a natural substance,such as oil from oil tankers into the sea.