There is no clear dividing line between what is good and what is bad.

是非之间没有明确的界限。

《牛津词典》

Her job is to liaise between students and teachers.

她的工作是做师生间的联系人。

《牛津词典》

The average age range is between 35 and 55.

平均年龄范围是35至55岁。

《柯林斯英汉双解大词典》

And the experts say the average age of people found to have the disease is between 20 and 50 years old.

VOA: special.2009.01.06

For example, he begins by borrowing the Russian formalist distinction in trying to explain what fiction is between plot and story.

举个例子，他开篇在解释那种文体介于情节和故事之间时,借用了俄国结构主义的特点。

耶鲁公开课 - 文学理论导论课程节选

I think the most important aspect is the relationship between myself and the client.

最重要的一点是正确处理我与客户之间的关系。

治疗心灵 - SpeakingMax英语口语达人

Half of American households are unmarried, and as big as the gap is between male and female voters, the gap between married and unmarried voters is even greater.

NPR: As Election Day Nears, Poll Data Questioned

Some research suggests that this may be the case, and that the lag between investments in IT and communications and productivity is between 5 and 15 years.

FORBES: The Economist: Innovation Almost Dead. Perhaps Not So In Electricity

The A470 is shut between Merthyr and Brecon and the M4 is shut between junctions 22 and 23 in both directions.

BBC: Snow latest across the UK