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D. speak 4.— Your hometown has changed a lot. — Yes. look at these tall buildings. They ___D___ last year. A. build B. built C. was built D. were built 5. — Why is the classroom so dirty? — Sorry, sir. It _____D__ yesterday. We fot to do it. A. don’t clean B. didn’t clean C. weren’t cleaned D. wasn’t cleaned Homework: Talk about and write them down. will you invent if you are an inventor? are the inventions used for? Thank you ! Goodbye !