in fits and starts:断断续续地,间歇地 not steadily, often starting and stopping

How's the book?
Oh, I'm working on it in fits and starts. I sometimes wonder if i'll ever finish it.

你的书怎么样了?
哦,写一阵停一阵,有时我都怀疑能不能完成.



fifty-fifty:平分的,二一添作五 divided equally between two people, groups or possibilities

let's split the bill fifty-fifty.
我们把账单平分吧.

she has a fifty-fifty chance of winning.
她有一半的获胜几率.