1.They boys went to a rock concert.(the theatre) 2.My mum drank a glass of juice in a cafe.(a glass of water)

1.The boys went to a rock concert.(the theatre)— Мальчики пошли на рок-концерт. — The boys went to the theatre.— Мальчики пошли в театр.  

2.My mum drank a glass of juice in a cafe.(a glass of water)— Моя мама выпила в кафе стакан сока. — My mum drank a glass of water in a cafe. — Моя мама выпила стакан воды в кафе.