It's not fair on the students to keep changing the timetable.

不断改动时间表，这样对待学生不恰当。

《牛津词典》

"I know this is hard on you," his mother said as he got ready for school this morning," and I'm really sorry you have to keep changing schools."

“我知道这对你来说很难，”今天早上他准备上学时，妈妈对他说：“我真的抱歉，你得不断换学校。”

youdao

I had to keep changing the angle every time she leaned over to talk to him, or he leaned over to kiss her.

每次她俯身跟他说话，或者他俯身吻她的时候，我都得不停地变换角度。

youdao

He had to revise the book in 2006 to keep up with the changing technology.

VOA: standard.2010.01.16

So, keep that in mind when we're talking about atomic radius, I'm not suddenly changing my story and saying, yes, we do have a distinct radius.

因此，当我们讨论原子半径的时候要时刻记住这一点，我并不是在突然改变自己的说法，说是的，我们的确有一个准确的半径。

麻省理工公开课 - 化学原理课程节选

It's one of the most rapidly changing, hard to keep up with areas because someone can set up an electronic exchange overnight and suddenly become a base for trading trillions of dollars of securities.

经纪业是一个变化最快的行业之一,人们很难跟上它的步伐,因为人们可以在头一天晚上,设置一个电子交易,一夜之间,他就能在证券市场赚到千亿美金

耶鲁公开课 - 金融市场课程节选

What if foreign competitors, from China and India, for example, keep changing the rules?

FORBES: 3 Things Business Can Learn From Government

So the numbers keep changing even if the voters are not having their say.

NPR: Political Junkie: Three Weeks to Pennsylvania

Self-improvement has forever been an American religion, but the norms about what is normal keep changing.

CNN: ASIANOW - TIME Asia | Brainteaser