问题
单项选择题 A1型题
内转换电子产生于以下哪一过程（）。
A.α衰变
B.光电效应
C.康普顿效应
D.γ衰变
E.湮灭辐射
答案
参考答案：D
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内转换电子产生于以下哪一过程（）。
A.α衰变
B.光电效应
C.康普顿效应
D.γ衰变
E.湮灭辐射
参考答案：D
Since 1980 there have been four major developments in TV. The first is video, which has given __1__ the power to control what they watch and when they watch it. These days, fifty percent of homes have a VCR (video-cassette recorder) and millions more are being sold every year. The second is satellite TV. Thanks to DBS (__2__), dozens of new channels are now __3__ to anyone who buys a receiving “dish”. The third development is cable－a system of hi-tech __4__, which provides even more channels. But not only that, cable also makes __5__ possible for you to communicate through your TV. Fourthly, there’s HDTV (high definition television), which now offers a much __6__ and more realistic picture than was possible even a few years ago. So more channels, more choice, more clarity (清晰). What is there left for __7__ to achieve in the future? The answer to that is two-way __8__. Modern technology means that 21st century televisions will be linked to computer data-banks. This way. Views will be able to ask questions about what they’re watching and the answers will appear on their __9__. This idea is called “hyper-media” and it’s still at an early __10__. But then, as we’ve just seen, TV had come a very long way in a very short time. The hyper0media revolution could happen sooner than any many people think.
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