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

c waves might (36) _______ to brain cancer. So far, the data are not conclusive. The scientific evidence does not (37) _______ us to say with certainly that mobile phones are categorically (38) _______. On the other hand, current research has not yet (39) _______ clear adverse effect associated with the prolonged use of mobile phones.

Numerous studies are now going (40) _______ in various countries. Some of the results are contradictory but others have shown an association between mobile phone use and cancer. (41) _______, these studies are preliminary and the issue needs further, long - term investigation.

(42) _______ the scientific data is more definite, it is prudent for people to try not to use mobile phone for long (43) _______ of time. Don't think that hands free phones are any safer either. At the moment, research is in fact showing the (44) _______ and they may be just as dangerous. It is also thought that young people (45) _______ bodies are still growing may be at particular risk.Question 42