there used to be river in front of the city didn't there?这句话

there used to be river in front of the city didn't there?这句话 there used to be a tall tree in front of the house.为什么要加be there used to be a beautiful garden in front of the house,__ There used to be a big tree in front of the house.（改为一般疑问） There used to be a big tree in front of the house.把此句改成否定句怎么 there used to be a tall tree in front of our classroom,_____ 英语翻译1.There used to be a tall tree in front of our classroom there is a river in front of the house改错 There used to be _________ near the river. There used to be lots of old city walls in beijing 的反意疑问句 There used to be lots of old city walls in Beijing.反意疑问句如何用? There used to be a clear river across the city 改一般疑问句并做否定回答