第17题: [单项选择]When I (got to) the cinema, the film (had already started); I (ought to) get there (earlier). A. got to B. had already started C. ought to D. earlier 参考答案:C 答案解析:句中是指过去“我”应该到早些。表示过去应该做某事而没做,要用ought to have got。
第18题: [单项选择]腭裂发生于 A. 胚胎第1~3周 B. 胚胎第4~6周 C. 胚胎第5~7周 D. 胚胎第8~12周 E. 胚胎第13周以后 参考答案:D