помогите пожалуйста с химией.
Для сжигания 80г серы израсходовали 285г воздуха обогощенного кислорода. Вычислить массовую долю кислорода в этом воздухе

Put the following questions into the Indirtct Speech:

1. "Why does the price go up so often?" she wondered.

2. "Are you working as well as you are studying?" asked Peter.

3. "Where were you last night, Mr.Jones?" he enquired.

4. "Will you have time to sign the documents?" asked the secretary.

5. "How long have you been here?" asked Mary.