Прочитайте текст и заполните пропуски A-F частями предложений, обозначенными цифрами 1-7. Одна из частей в списке лишняя.

1. depending on the survey and the time of year

2. rotating disk with holes arranged in a spiral pattern

3. could be measured in the thousands

4. could capture moving images

5. funding a number of research programmes

6. transmitting images 16 years before

7. had lived in a house without electricity

Few inventions have had as much effect on contemporary society, especially American society, as television. Before 1947 the number of U.S. homes with television sets A ______ . By the late 1990s, 98 percent of U.S. homes had at least one television set, and those sets were on for an average of more than seven hours a day. The typical American spends (B ______ ) from two-and-a-half to almost five hours a day watching television.

The invention of TV is not credited to one single person. Vladimir Zworykin and Philo Farnsworth both played instrumental roles. Electronic television was first successfully demonstrated in San Francisco on Sept. 7, 1927. The system was designed by Philo Taylor Farnsworth, a 21-year-old inventor who C ______ until he was 14. While still in high school, Farnsworth had begun to think of a system that D ______ in a form that could be coded onto radio waves and then transformed back into a picture on a screen. Boris Rosing and Vladimir Zvorykin in Russia had conducted some experiments in E ______ Farnsworth’s first success.

Also, a mechanical television system, which scanned images using a F ______ , had been demonstrated by John Logic Baird in England and Charles Francis Jenkins in the United States earlier in the 1920s. However, Farnsworth’s invention and Vladimir Zvorykin’s electronic TV system are the direct ancestors of modern television.