1. The return of the echo will elapse longer time.
    回声返回所耗的时间越长了.

2. The further off this solid obstruction, the longer time will elapse for the return of the echo.
    固体障碍物越远。回声返回所用时间就越长。

3. Unless a certain amount of time is allowed to elapse, it seems in their eyes as if the task being considered were insignificant, not worthy of proper respect.
    在他们看来，如果不是花一定时间来处理某件事的话 ，则这件事就好像是无足轻重的，不值得给予适当的重视。