1. A thorn in someone's side

腰上的荆棘(芒刺在背)

He is a thorn in my side. = He bothers me or restricts me.

他让我觉得芒刺在背.

例子: His accent has always been a thorn in his side. He is very intelligent, but no one can understand him.

他说话的声音让我觉得芒刺在背.他是个聪明得人, 但是谁也听不懂他的话.

2. Back on track

重上轨道（改过自新）

I am back on track. = I am once again pursuing the correct goal.

我又开始追寻正确的目标了。

例子： She used to drink a lot after work and the next day it would affect her job, but now she has a boyfriend and that has helped put her back on track.

以前她下了班就酗酒，以致影响第二天的工作表现。 现在她心认识论了一个男朋友，那有助于她重上轨道。

3, An uphill battle

上坡作战(在逆境中求胜)

It was an uphill battle. = It was very difficult and we felt like we were not going to accomplish it, but we did.

这件事好比上坡作战,很不容易.我先前还以为做不到,结果却办成了.

例子: Making my parents believe that it was a good idea for me to delay college and travel instead was an uphill battle. I promised that I would go to college after one year, so they agreed.

说服我父母让我辍学去旅游好比作战.我答应他们一年以后回来上大学,他们终于答应了.