25. a) We have usually lunch at 12 o'clock. b) We usually have lunch at 12 o'clock. c) We have lunch at usually 12 o'clock. d) We have lunch at 12 usually o'clock.

В английском языке наречия частотности (usually, often, always, sometimes, never) ставятся перед основным глаголом, но после глагола to be.

b) We usually have lunch at 12 o'clock - Обычно мы обедаем в 12 часов.

Ответ: b