пожалуйста я не могу ((((((( даю 20 баллов

1. The first bike with pedals was invented in 1840.
2. The bike on the right was invented 30 years later. It was faster than the first bike.
3. Riding a bike is healthy because it helps you to keep fit.
4. Which of these leaves the most poisonous gases in the air in big cities? Factories?