Lily had left ______ the time we arrived.

【小题1】Lily had to walk for another two hours. (一般疑问句)
______ Lily _______ to walk for another two hours?
【小题2】The Greens will be back in two weeks. (对划线部分提问)
_______  ________ will the Greens be back ?
【小题3】They will spend two years building a new bridge over Changjiang River. （同义句）
It will ______ them two years to ______ a new bridge over Changjiang River.
【小题4】汤姆是我们班上跑得最快的学生。（完成句子）
Tom runs faster than ________  _________ in our class.