39. The main disadvantage of mobile phones is that A. they are expensive. B. they are bad for our health. C. they create stress.

Ответ (EN):

The main disadvantage of mobile phones is that B. they are bad for our health.

Перевод (RU):

Главный недостаток мобильных телефонов в том, что B. они вредны для нашего здоровья.