Choose the grammatically correct sentences. More than one answer is possible.

Tick the correct answers.

• By the year 2050, people will have changed their lifestyle.
• English classes will already begin by the time she arrives at school.
• What will she have achieved by the time she will be 30 years old?
• By the time I'm 70 years old, I will have seen 50 countries.
• I don't tell you everything by then.