What impact can mobile phones have on their users" health Many people worry about the supposed ill effects caused by radiation from handsets and base stations, (1)_____ the lack of credible evidence of any harm. But evidence for the beneficial effects of mobile phones on health is rather more (2)_____ Indeed, a systematic review (3)_____ out by Rifat Atun and his colleagues at Imperial College, rounds up 150 (4)_____ of the use of text-messaging in the (5)_____ of health care. These uses (6)_____ three categories: efficiency gains; public-health gains; and direct benefits to patients by (7)_____ text-messaging into treatment regimes. Using texting to (8)_____ efficiency is not profound science, but big savings can be achieved. Several (9)_____ carried out in England have found that the use of text-messaging reminders (10)_____ the number of missed appointments with family doctors by 26-39%, and the number of missed hospital appointments by 33-50%. If such schemes were (11)_____ nationally, this would translate (12)_____ annual savings of ￡256-364 million. Text messages can also be a good way to deliver public-health information, particularly to groups (13)_____ are hard to reach by other means. Text messages have been used in India to (14)_____ people about the World Health Organization"s strategy to control lung disease. In Iraq, text messages were used to support a (15)_____ to immunize nearly 5 million children (16)_____ paralysis. (17)_____, there are the uses of text-messaging as part of a treatment regime. These involve sending reminders to patients to (18)_____ their medicine, or to encourage accordance with exercise regimes. However, Dr. Rifat notes that the evidence for the effectiveness of such schemes is generally (19)_____, and more quantitative research is (20)_____.

A. off
B. with
C. against
D. in