6. The house is so spacious that the children can run up and down. (ENOUGH)

⇒ The house is spacious enough for the children to run up and down

7. The best thing for you to do is to ask the teacher. (SHOULD)

⇒ You should ask the teacher

8. The air pollution level has increased rapidly since the previous century. (INCREASE)

⇒There has been a rapid increase in the air pollution since the previous century.

9. Harmful chemicals released into the environment can cause health problems. (RESULT)

⇒ Health problems can result from harmful chemicals released into the environment.

10. Nowadays, many young boys are computer game addicts. (ADDICTED)

⇒Nowadays, many young boys are addicted to computer games.