People have been reluctant to make formal complaints to the police.

人们一直不愿正式向警方投诉。

《柯林斯英汉双解大词典》

Today, our customer sent a letter of formal complaints to our General Manager.

今天，偶们的客户给总经理发了一封正式的投诉信。

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The public may lodge formal complaints against ICAC officers to the ICAC Complaints Committee.

市民如欲投诉廉政公署职员，可向廉政公署事宜投诉委员会正式提出。

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The public can submit comments until September 26 and formal complaints though January 2013.

CNN: Saudi Arabia objects to .gay and .islam domain names

Victims had been reluctant to make formal complaints "because we didn't want any of this fuss", she added.

BBC: UK Politics

However, he said the instant apologies often appeased travellers to an extent they then did not bother to make formal complaints.

BBC: London Midland: Train drivers' union blames pay levels