I just go by what I see on the river as I walk it down.只通過漫步河畔途中所見來判斷。

go by:經過, 走過

He was watching the crowd go by.

他注視著人群走過。

Saturday afternoons go by like lightning!

星期六的下午象閃電一樣轉瞬即逝！

I back and forth every day on the river我每天都在河畔來回漫步

back and forth:來回地, 反復地

He rocked back and forth in his rocking chair.

他坐在搖椅里前后搖晃著。

He fluttered back and forth in the corridor.

他在走廊上煩躁不安地走來走去。

but in the meantime,the people of Hay River have a remarkable guardian.但同時草河的居民擁有優秀的守護者

in the meantime:與此同時, 在此期間

In the meantime, he gave me a lot of good advice.

同時他給我提了很多好的建議。