你们若大力协助尽快把大厅腾空，我们将不胜感激。
We would be grateful for your cooperation in clearing the hall as quickly as possible.
若能及时将图书归还图书馆，我们将不胜感激。
We would appreciate the prompt return of books to the library.
如能把这些变化通知相关部门，我们将不胜感激。
We will appreciate your informing the appropriate departments of these changes.
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