单项选择题

The (1) of the fluorescent tube (2) a major revolution in the development of better and cheaper lighting. First shown at the New York and San Francisco World (3) in 1939, this more efficient, more diffuse, longer-lived lamp has been (4) improved, so that slowly it (5) the supremacy of the incandescent household globe. The fluorescent tube (6) Australian homes, shops and factories today is seven or eight times (7) thetubes that brought shadow-free lighting to many of Britain’s wartime factories. Its (8) too, is much greater — from 2, 000 hours in 1940 to mc/re than 7, 500 hours today.
But (9) its (10) use for more than 30 years, the fluorescent tube remains a
(11) to many of its users. It is built (12) a completely different (13) from the incandescent light. In the incandescent bulb, a tungsten wire (14) than a human hair, is brought to white-hot temperature by passing an electric (15) through it. In the fluorescent tube a stream of electrons bombards a gas containingmercury, (16) invisible ultraviolet radiation. The ultraviolet rays hit the fluorescent coating that (17) the tube, (18) it to grow. A 40 watt ’fluorescent tube gives twice as much light as a 100 .watt tungsten globe, (19) about five times as long, and runs cool enough to (20) higher levels of light.

Read tile following text. Choose the best word(s) for each numbered blank and mark A, B, C or D on ANSWER SHEET 1.1（）

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