5) My brother is very lazy. He often cleans his room-only once a month!

В данном предложении необходимо выбрать подходящее слово, чтобы оно сочеталось с остальной частью предложения.

Подставим варианты:

1. My brother is very lazy. He often cleans his room-only once a month!

Предложение имеет смысл.

Ответ: My brother is very lazy. He often cleans his room-only once a month!