"White noise" was played into the subject's ears through headphones.让受试者通过耳机听“白噪声”。One hundred and forty quid for a pair of headphones, you've got to be joking!一副耳机140英镑，你不是在开玩笑吧！I refused to wear headphones be...
牙医可能会决定拔掉那颗牙，以免反复发作。A dentist may decide to extract the tooth to prevent recurrent trouble.牙斑如果不清除就会导致牙齿蛀蚀和牙龈疾病。When not removed, plaque causes tooth decay and gum disease.餐后要刷牙，而且每天要使用牙线清洁牙缝。Brush your teeth after each ...