3. Trafalgar Square is often referred to in the British press as a place where mass meetings and demonstrations

Задание 3

В последнем абзаце читаем: «Like Hyde Park, Trafalgar Square is often referred to in the British press as a place where mass meetings and demonstrations are held. The traditional anti-war march is among them.» Следовательно, пропущенное слово — «are held».

Ответ: are held