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| 文章出处：学生大考试站 发布时间：2005-10-12 |
owerful beam. This light is particularly powerful when it travels in coherent waves,
that is, waves which are all the same length and
52. _____
which move in step. For this reason, too, this light consists of only one colour, and
not of many colours unlike sunlight.
53. _____
Light of this strength can be very useful and has already found much different
applications in science. One important use of laser is to measure distance.
54. _____
The astronauts on one Apollo mission set up a reflector on the moon to "catch"
laser beams projected from the earth and to return them to our planet. By measuring
the time the beam takes to go to the moon and comes back, scientists
55. _____
can add the precise distance.
56. _____
Other use of lasers is to measure time. The fact that their pulses can be
57. ____
used to divide a single one second into very small parts. In fact, pulses of laser
58. _____
light that last only one pico-second have already been produced.
Laser beams can be used in communications, either. A laser beam traveling
59. _____
through an enclosed tube can carry as much informations as 80 million TV channels.
60. _____
Part V Writing
Directions:
For this part, you are allowed 30 minutes to write a composition. The opening
sentence is given and you are required to develop it into a full composition. Your
part of writing should be no less that 120 words.
Foreign Investment In China
Thanks to the open policy in China, more and more foreign businessmen have
come to invest. . .
考题答案：cbdcc bdacd accaa aabdd babcc ccbdc dbcad dbaaa adacb bcadd 51. after -/ 52. when-because 53. unlike-like 54. much-many 55. comes-come 56. add-calculate 57. other-another/the other 58. one-/ 59. either-too 60. informations-information
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