Ifthenewsafetysystem的精选

问题详情：Ifthenewsafetysystem_______touse,theaccidentwouldneverhavehappened.A．hadbeenput       B．wereput              C．shouldbeput     D．wouldbeput【回答】A 【详解】考查虚拟语气...

问题详情： Ifthenewsafetysystem_______touse,theaccidentwouldneverhavehappened.      A.hadbeenput             B.wereput             C.shouldbeput    D.wouldbeput【回...