1. Peter didn't study hard, so he failed the exams.-Peter failed the exams because he  didn't study hard
2. Lan is the best student in her class.-No one in the class stuies better than Lan
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3. People collect and send the glass to the factories.-The glass is collected and sent to the factories
4.Our gers are now better equipped than in the past. (badly)-In the past, our gers were more badly equipped than now
5.A sports car goes faster than an ordinary car. (slowly)-An ordinary car goes slowlier than a sports car
6. It is not necessary for us to spend too much time studying. 
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-You don't....HAVE TO spend too much time studying
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7. You have a smooth voice! WHAT.. a smooth voice you have!
8. Danny doesn't solve the problem as carefully as Eddy. Eddy solves the problem MORE carefully than Danny
9. They will widen the gate to let the cars run into the yard easily.-> The gate..... will be widened to let the cars run into the yard easily
10.The last time Phong visited Tasmania was five years ago.-> Phong hasn't.. visited Tasmania for five years