They happened to _____ for Tianjin when we got there. A.leave B. have left C.leaving D. had left答案是B,求解释为什么不填A,词组中不是应该用原型吗?

Yesterday something ___(usually)happened to him What do you think happened to they? -what ___ one Sunday morning -Nothing A、happens to them B、 did they happenC、did happen to them D、happened to them what happened to you的同义句what ___ ___ to you?what's ___ ___you? --What _ to them?--they appeared__in the accident.A.has happened to,be injured B.happened ,to have been injuredC.has happened to ,be injured D.happened ,injured 英语翻译___ They ___ ___ go to the ___ ___?Yes,they ____.____,they ____. 英语翻译___ They ___ ___ go to the ___ ___?Yes,they ____.____,they ____. 选择 What ___ him just now?He is unhappy.A.happened B.happened to C.happening D.happened with Do you know what ___ yesterday?A.he happenedB.happened himC.he happened toD.happened to him didn't know what ___ to her last night.A.was happened B.happen C.happened D.is happened I don’t know what ___ last night.用he happened 还是happened to him 为什么 what happened to Tom yesterday ___ ____ ___ ___ Tom yesterday改为同义句 请问What do you think happened to they? do you know what happened to them还是do you know what they happened为什么？ Happened to /happened with 区别 they don't know what ————yesterdayA.did he happen B.he happened C.happened to him D. was happened to him they don't know what ————yesterdayA.did he happen B.he happened C.happened to him D.was happened to him They were hurrying to catch their train.They were ___ ___ ___ to catch their train