Many of the modern world's most famous inventions__1__by amateur inventions. often, these inventions had such strange ideas __2__they were laughed at. But people like these, working on thier own, gave us many of the things we use every day. Clarence Birdseye,__3__invented frozen food, was both a successful inventor and a good businessman. But it took him years to overcome the biggest problem of successful inventions:persuading people to try something new and different. Birdseye first tried to freeze fish. After years of experimenting, he started Birdseye Seafood Company. It was a ong time _4__people finally accepted frozen food. A. are made B. were made C. have been made D. had been made 2. A. as B. than C. like D. that 3. A. which B. whom C. who D. whose 4. A. before B. that C. after D. as