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 from 23 to 27. Fill in the appropriate word in question 23
Mobile phones emit microwave radio emissions. Researchers are questioning whether exposure to these radio waves might (23) _________ to brain cancer. So far, the data are not conclusive. The scientific evidence does not enable us to say with certainly that mobile phones are categorically (24) _________. On the other hand, current research has not yet proved clear adverse effect associated with the prolonged use of mobile phones.
Numerous studies are now going on in various countries. Some of the results are contradictory but others have shown an association between mobile phone use and cancer. (25) _________, these studies are preliminary and the issue needs further, long - term investigation.
(26) _________ the scientific data is more definite, it is prudent for people to try not to use mobile phones for long periods of time. Don’t think that hands free phones are any safer either. At the moment, research is in fact showing the (27) _________ and they may be just as dangerous. It is also thought that young people whose bodies are still growing may be at particular risk.
A. cause
B. bring
C. produce
D. lead
