Ifthenewsafetysystem的精選

問題詳情： Ifthenewsafetysystem_______touse,theaccidentwouldneverhavehappened.      A.hadbeenput             B.wereput             C.shouldbeput    D.wouldbeput【回...

問題詳情：Ifthenewsafetysystem_______touse,theaccidentwouldneverhavehappened.A．hadbeenput       B．wereput              C．shouldbeput     D．wouldbeput【回答】A 【詳解】考查虛擬語氣...