The satellite will be used mainly to relay television programmes.

这颗卫星将主要用来转播电视节目。

《柯林斯英汉双解大词典》

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Most students attend a university mainly to acquire the knowledge needed for their chosen profession.

大多数学生上大学主要是为了获得他们所选择的职业所需的知识。

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They began to consider that their job was mainly to provide information.

VOA: special.2009.04.20

You can use them mainly to soften your speech.

你可以用它们来柔化你的言辞。

Would you 课堂 - SpeakingMax英语口语达人

It probably is at least in part, but mainly it is probably intended to be fiction or fictionalized biography.

最少一部分是，可是结果大相径庭,大篇都是虚构或文学小说化了的自传。

耶鲁公开课 - 1945年后的美国小说课程节选

Its locker seems designed mainly to be a ruse to sell more ringtones and games.

FORBES: The Mobile Locker

Your pal, Glen Beck, for example, appeals mainly to people over the age of 55.

FORBES: GOP Launching Multi-Pronged Attack On Senior Citizens

Visa processes for those professionals are usually tied mainly to a job offer in the country.

BBC: How it's worked out