1. . The river is so rough that the children couldn't swim in it. TOO 2. 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. 3. The furniture was so expensive that I didnt buy it. The furniture was too 4. Her parents allowed her to go out with me last night. (LET) 5. It takes us twenty minutes to walk to the supermarket. (SPEND) 6. I'd advise Nam get home early. (should) 7. It is necessary for my daughter to tell me about the accident. (must) 8. It would be a good idea for him to apologize to his wife because she was not wrong. (ought) 9. The number of young people working on farms has decreased sharply. DECREASE There has 10.My friend didnt come to my party I wish 11. You cant visit the USA unless you have a visa. If 12. Its very inconvenient if you cant drive. (able)