他们正式提出抗议。用英语怎么说？

他们正式提出抗议。

They were formally protesting.

they

pron. 他/她/它们，人们，大家，政府，当局，她们；

例句
The storms had abated by the time they rounded Cape Horn.
他们绕过合恩角时，暴风雨已经减弱。

were

be的过去时复数和第二人称单数形式，有时代替 was,用于条件从句、动词 wish 之后等；

例句
Shops, houses, and vehicles were set ablaze.
店铺、房子和车辆全都陷于火海。

formally

adv. 正式地，正规地，拘泥形式地，形式上；

例句
Two years ago, Congress formally apologized for the internment...
两年前，国会就此拘留事件正式道歉。

protesting

v. 声明( protest的现在分词 )，坚决地表示，申辩；

例句
They have been protesting about fumes from a chlorine factory.
他们一直在抗议一家氯工厂排放有毒气体。