Language Point 40

...spent an hour or two trying a great number of combinations, but he arrived at no result. (Para. 5)
Meaning : ...spent a couple of hours trying many, various combinations, but he made no success.
spend (time) doing something: pass the time doing sth.
He spent an hour each day exercising.

他每天花1小時運動。
Now more and more city adults spend their free time trying to improve themselves at school or college.

現在城市里越來越多的成年人利用業余時間到學校或大學去充電。
Compare: spend (time) on something
He doesn't spend much time on his homework .

他花在作業上的時間不多。