【单选题】

Scientists who believe cell phones are dangerous have been throwing out hypotheses to explain away the negative results. Maybe something about the (31) animals raised their rates of cancer or sperm problems, so (32) the exposed animals didn’t seem to be harmeD、Maybe the studies should have used pulsed, (33) radiation rather than a continuous beam, the better to (34) the way we actually use mobile phones. Maybe it matters (35) the lab animals are zapped (36) in a device like a Ferris wheel or while (37) around in cages. On the other hand, if these details do (38) , maybe that in itself is significant.

Scientists who (39) claims that cell-phone radiation is causing an epidemic of brain cancer (40) that there isn’t any mechanism. (41) textbook biophysics, only radiation that has enough energy to ionize molecules—that is, knock off electrons—can (42) cancer.Cell phones don’t (43) energy great enough to ionize molecules in living cells. Their (44) is "far below the cancer energy threshold," (45) physicist Robert Park of the University of Maryland, who often (46) junk science.But whenever he makes that (47) in his What’s New e-newsletter, he gets (48) with angry responses insisting there are other ways low-energy radiation can (49) . "I don’t like cell phones and I don’t like writing about cell phones," says Park, " (50) the damned issue just won’t go away.\
A．battles
B．conquers
C．copes with
D．confronts with