[填空题]
Workers around jet aircraft ty ;wovtye n+y84picallyt:rp4d 90pgm vwcf52q wear protective devices over their ears. Assume that the sound level of a jet airplane engine, at a distance of 30 m, is 140 dB, and that the average human ear has an effective radius of 2.0 cm. What would be the power intercepted by an unprotected ear at a distance of 30 m fp5t0:pcwvgmrd 24f9q rom a jet airplane engine? W
