讲解：
pit sb / sth against sth
使竞争；使较量；使经受考验:
Lawyers and accountants felt that they were being pitted against each other.
律师和会计师都觉得他们要一争高下。

learn (sth) (from sb / sth）
学；学习；学到；学会:
You can learn a great deal just from watching other players.
你只要注意看其他运动员怎样动作就能学到许多东西。

crack on (with sth)
(为尽快完成而)努力干；(急速)经过,穿过；快速继续下去:
Time was cracking on and we were nowhere near finished.
时间飞逝,可我们却远远没有完成。

I reckon that…
想；认为:
It's worth a lot of money, I reckon.
我想这值很多钱。

roll up
到达:
Roll up! Roll up! (= used to invite people who are passing to form an audience)
快来看哪！快来看哪！

stand a chance (of doing sth)
有可能成功；有机会获得:
The driver didn't stand a chance of stopping in time.
司机没有来得及刹车。

oscillate (between A and B)
（情感或行为)摇摆,波动,变化
Her moods oscillated between depression and elation.
她的情绪时而抑郁,时而亢奋。