41.   But analysts predicted the effect would not last long as other oil producers would make up the short fall.

42.   But the roller coaster effect lasted several hours.

43.   But this study followed patients for longer and found the effects can last at least four years.

44.   He said the beneficial effect lasted for at least eight months.

45.   Its effects last for much longer, continuing even after therapy.

46.   The effects can last for several years.

47.   Viagra is taken an hour before sex, and the effect can last as long as a day.

48.   There is also some debate over how long the effects will last in the atmosphere.

49.   The exhilarating effect lasts for a few hours, reputedly enabling the user to resume a normal social life without problems.