You’ll never work it out by that method; you are _____ altogether A.keeping track of B.off the track C.on the track of D.around the track 答案:B考查固定短语。句意是:用那种方法你永远也解不出的,你全部做错了。keep track of保持联系;off the track想法或作法不对;on the track of未离题的;around the track围绕。 A元素的阳离子、B元素的阴离子都具有相同的电子层结构.则A、B元素原子序数大小是( )A.B<AB.A<BC.B=AD.A=B+2