Read the following passage and mark the letter A, B, C, or D to indicate the correct word or phrase that best fits each of the numbered blanks.

The mobile phone
People have been dreaming of having a personal means of communication for a long time. In the late 1960s, the idea seemed so far in the future that it was included in the science fiction series, Star Trek. Since the 1980s, however, mobile have become a part of everyday life. (37) _________ they were initially seen as a status symbol for successful business people, mobile use has spread to include practically everyone in the developed world, old and young alike The (38) __________ on social life has been enormous. We have got used to the idea of having constantly changed social plans, (39) _______ a quick phone call is all takes to rearrange things. Before this was possible, there were (40) _________ occasions when friends who had arranged to meet completely missed each other because of a slight misunderstanding. People would often have to (41) _________ very careful arrangements to be sure of meeting up. As mobiles have become more popular, so they have become more powerful. The large, unreliable mobile phone of the 1980s has evolved into the small stylish phone of today.