All income must be declared.

所有收益必须申报。

《牛津词典》

Any class that declares an abstract method must itself be declared abstract.

声明抽象方法的任何类本身必须是声明为抽象的。

youdao

The mutex object must be declared; once declared, it must be initialized.

互斥量对象必须先被声明；声明后还必须初始化。

youdao

In nineteen twelve, Congress declared how the stars must be shown.

VOA: special.2010.04.02

Iraq sent a letter to UN Secretary General Kofi Annan saying it would "deal" with the resolution passed unanimously in the Security Council last week that all weapons of mass destruction must be declared and inspected.

BBC: World urges Iraq to comply

They must be unloaded and declared to the airline, and passengers must follow local gun laws.

CNN: Airport screeners discover more than 1,500 guns in 2012

In addition, potential candidates must secure the declared support of at least 200 party members from at least 20 local parties.

BBC: The path to leadership