3 A: ________ B: They've played hockey together ____ 2016.

Решение:

В пропуске нужно использовать слово 'since', так как указан конкретный год начала (2016).

1. A: How long have they played hockey together?
2. B: They've played hockey together since 2016.

Ответ: 3. A: How long have they played hockey together?