单项选择题 患儿2岁，智力低下，体格发育迟缓，眼距宽，鼻梁低平，眼裂小，有内眦赘皮，外耳小，舌常伸出口外，头围小于正常，出牙延迟，四肢短，关节可过度弯曲，atd角增大。最可能的诊断为

未知题型 We wanted to go out yesterday but the weather was terrible. If it ______ a nice day, we ______for a picnic.A．had been; would have goneB．was, would goC．were; would have goneD．would be; would go

未知题型 世界上第一部论述教育教学问题的著作是（ ）。