I won’t tell the student the answer to the mathproblem until he on it for more thanan hour

＄1，500， butthat’s my last offer— OK It’s a ____

为了向普通读者介绍中国古代园林中“窗”的艺术作用，建筑学家引用下面哪句诗文最为贴切（ ）

mmittee had met many times,but had not come up with __________ to the problem

I am very worried about tomorrow’s math test. I am afraid I can’t pass this time.–___________! I’m sure you’ll be successful.