阅读下面的短文，文章中有5处空白，文章后有6组文字，请根据文章的内容选择5组文字，将其分别放回文章原有位置，以恢复文章原貌。 (46) Picturephone service, which will
become available commercially in the 1970s, will at first probably be used by
large business corporations. (47) It is already clear that
"the next best thing to being there" is going to be a Picturephone
call. (48) This "new light", first produced
by scientists in 1960, can beam continuously and with extraordinary
intensity. (49) In other words, they are thinking of using
light for the same purpose radio waves are used—to transmit telephone calls, TV
programs, and data messages from one point to another. With the expansion of
Picturephone service and highspeed data communications between computers,
present message-carrying capacities may soon become inadequate. As it turns out
to be technically and economically’ sound, the laser might prove to be a major
breakthrough in telephone communications. Current research in
telephone communications is so extensive and changes are coming about so rapidly
that no one can predict with accuracy what the telephone of tomorrow will look
like. (50) 。 A. But as Picturephone
service becomes available, it will no doubt spread from the office to the
home. B. Instead of using light to see by, telephone
researchers are thinking of ways to use light to communicate by.
C. For many people the most’ exciting development in recent years
is Picturephone service. D. One area that is being
seriously considered is communications service "on the move".
E. But there is at least one prediction that can be made with assurance:
There will be more and more telephones in the future, and they will be better
ones. F. Possibly the most significant research now being
conducted is in the use of the laser beam in telephone communications.