5．How long has 3-D technology been around？Most of us might think of crowds of teenagers in a 1950's movie house watching Bwana Devil in 3-D．But 3-D technology made its first appearance on the scene in 1838with the first stereoscope（体视镜）．And the first actual 3-D movie was a 1903 film called Le Ariveed'un Train．
Although it has such a long history，the technology has still remained based on one simple principle-----to make 3-D effects you must find a way to project two slightly different pictures to each eye．Modern 3-D technology works by rapidly flickering（闪动） two versions of the movie and projecting them onto each eye．The brain does the rest of the work，combining the two pictures together into one and giving the show the appearance of depth，the third dimension．
But does this exposure，especially long exposures，cause harm to the child's developing brain and visual system？Unfortunately，long-term studies on new flicker digital 3-D technology and children aren't yet available．We do not know if regular or daily 3-D viewing over years affects the developing visual system，although older 3-D methods basically do the same thing and are not considered harmful．
The question of possible harm in modern 3-D use in TV is really based on two facts：the amount of time children will now be watching 3-D TV each day and the sensitivity some children show in reaction to 3-D viewing．It is difficult to make actual lab studies of longer term 3-D viewing in children because of the possible harm of the experiment．Researchers will have to wait until 3-D TV technology is already in the marketplace for a number of years，then check heavy 3-D TV watchers and compare them with non-watchers．
With a 3-D television technology in the home，we will soon be able to answer the question of whether or not longer and more frequent periods of 3-D exposure cause more changes in the visual system．We may find that the bigger problem is the introduction of a new technology that leads to even more time spent on TV rather than playing outdoors．
8．According to the text，3-D technologyD
A．was refused by people when it first appeared．
B．will soon change the way we watch TV．
C．does no good to our visual system．
D．has a history of nearly 200 years．
9．Paragraph 2is mainly aboutA
A．how 3-D technology works．
B．why 3-D movies are popular
C．the history of 3-D technology．
D．the influence of 3-D technology．
10．What's the method suggested in paragraph 4？A
A．To wait and see
B．To carry out lab studies
C．To stop making 3-D movies
D．To improve 3-D technology
11．The author's purpose in writing the text is toB
A．ask children not to watch 3-D movies．
B．discuss if 3-D viewing is harmful to children．
C．introduce the advantages of 3-D technology．
D．predict the development of 3-D technology．
分析 本文介绍了3-D技术有很长的历史，不仅给我们带来了视觉上的享受同时也给孩子们带来了一些负面影响，孩子们看电视的时间要比户外运动时间长．
解答 8．D．细节理解题．由文中的"3-D technology made its first appearance on the scene in 1838 with the first stereoscope（体视镜）．"可知，3-D技术大概有200年的历史了，故选D．
9．A．段落大意题．文章第二段．But 3-D technology made its first appearance on the scene in 1838 with the first stereoscope主要介绍的是如何形成3-D影像的，故选A．
10．A．细节理解题．由该段最后一句话"Researchers will have to wait until 3-D TV technology is already in the marketplace for a number of years，then check heavy 3-D TV watchers and compare them with non-watchers．"可知，办法就是等待，然后观察，故选A．
11．B．写作意图题．根据We may find that the bigger problem is the introduction of a new technology that leads to even more time spent on TV rather than playing outdoors可知作者写本文的意图是为了讨论观看3-D影片是否对孩子有害．答案为B．
点评 考察学生的细节理解和推理判断能力，做细节理解题时一定要找到文章中的原句，和题干进行比较，再做出正确的选择．在做推理判断题不要以个人的主观想象代替文章的事实，要根据文章事实进行合乎逻辑的推理判断．
