根据要求改写下列句子，每空一词
【小题1】The bird is singing in the tree.（改为一般疑问句）
__________ the bird __________ in the tree？
【小题2】The girl is waiting for her mother.（改为否定句）
The girl __________ __________ for her mother.
【小题3】How much are these trousers？（同义句转换）
__________ the __________ of these trousers？
【小题4】Thank you for your help.（答语）
__________ __________.
【小题5】Lily likes walking after supper.（对画线部分提问）
__________ __________ Lily __________？