“坚持”的表达：
cling on to sth 坚持，不愿放弃
This girl is clinging on to the hope that she would be cured.
这个女孩坚持相信自己是可以被治好的。

句型：cling on to the hope/belief/idea etc (that).....
She managed to cling on to life for many years.
她顽强地又活了很多年。

cling on to life 顽强地活下去
He had one last hope to cling on to.
他还抱着最后的一丝希望。

to/until the bitter end （不怕艰苦）坚持到底，奋斗到底
They were prepared to fight to the bitter end.
他们准备好了要坚持到底。
We might not have a chance of winning today, but we have to give it our all until the bitter end!
我们可能没法赢，但是我们必须拼尽全力，奋斗到底！

“放弃”的表达：
chicken out of sth/doing sth 因害怕而放弃，临阵退缩，胆怯
I chickened out of going bungee jumping.
我不敢蹦极。
I chickened out of seeing the horror movie.
我不敢看恐怖电影。

chicken n.胆小鬼
Don't be a chicken.
别怕！
Don't be a chicken！Try these chicken's feet.
别怕！尝尝这个鸡爪！

deep-six 放弃，抛弃
People ask her to deep-six her hope for life.
人们叫她放弃活着的希望。