Many schools have banned experiments seen as dangerous, even though they teach (47) skills. It is a scientific fact, tested and (48) by generations of pupils, that experiments in school laboratories win young people to the cause of science. White coats, goggles and the chance to set fire to things (49) a passion for chemistry that even years of examinations do not (50) . But government advisers and scientists are warning of a disturbing development that could endanger generations of future scientists: pupils are no longer allowed to experiment. Health and safety concerns are preventing students — including those taking A levels — from (51) vital and exciting investigations into what happens when one sets fire to magnesium(镁) ribbon, or drops a small glob of sodium(钠) into a dish of water. The fear of burns and volatile reactions means that even ordinary procedures such as distillation are often viewed online rather than performed in the laboratory. A report warned that the national (52) and testing system led to boring science lessons. Schools spent too much time (53) students for tests, it said. Jane Lees, head of Hindley High School in Wigan, and a former head of science, agreed that health and safety had put an end to a number of "whiz-bang" experiments. "But we’re moving on to different ways of teaching science — with videos, and on the web with (54) learning environments which are (55) as interesting. It’s a different way of learning but it should still be able to turn them on. What you need is (56) teachers. " A. performing I) quite B. extinguish J) approved C. playing K) curriculum D. vital L) inspirational E. fatal M) distinguish F. foster N) virtue G. drilling O) virtual H) proven