Until a few years ago, what the most doctors could do was to counsel patients with bad breath about oral cleanliness. Now they are finding new ways to treat the usually curable condition. Bad breath can happen whenever the normal flow of saliva slows. Our mouths are full of bacteria feeding on protein in bits of food and shed tissue. The bacteria emit evil-smelling gases, the worst of which is hydrogen sulfide. Mouth bacteria thrive in airless conditions. Oxygen-rich saliva keeps their numbers down. When we sleep, for example, the saliva stream slows, and sulfide-producing bacteria gain the upper hand, producing classic "morning breath".
Alcohol, hunger, long time talking, breathing through the mouth during exercise-anything that dries the mouth produces bad breath. So can stress though it's not understood why. Some people's breath turns sour every time they go on a job interview.
Saliva flow gradually slows with age, which explains why the elderly have more bad-breath trouble than younger people do. Babies, however, who make plenty of saliva and whose mouths contain relatively few bacteria have characteristically sweet breath.
For most of us, the simple, dry-mouth variety of bad breath is easily cured. Eating or drinking starts saliva and sweeps away many of the bacteria. Breakfast often stops morning breath. Those with chronic dry mouth find that it helps to keep gum, hard candy, or a bottle of water or juice around. Brushing the teeth wipes out dry- mouth bad breath it clears away many of the offending bacteria.
Surprisingly, one thing that rarely works is mouthwash. The liquid can mask bad- breath odor with its own smell, but the effect lasts no more than an hour. Some mouth- washes claim to kill the bacteria responsible for bad breath. The trouble is, they don't necessarily reach all offending germs. Most bacteria are well protected from mouthwash under thick layers of mucus. If the mouthwash contains alcohol--as most do--it can intensify the problem by drying out the mouth.
The phrase "emanate from" in Paragraph 1 most probably means "______".
A.thrive on
B.account for
C.originate from
D.descend from
第1题
A.运用中药和针灸、拔罐、推拿等非药物疗法开展诊疗服务
B.提供中药调剂、汤剂煎煮等中药药事服务
C.存在不可控的医疗安全隐患和风险
D.开展西医诊疗服务
第2题
A.中药
B.针灸
C.拔罐
D.推拿
第3题
第6题
第9题
A.一万元以上五万元以下
B.三万元以上五万元以下
C.一万元以上三万元以下
D.三万元以上十万元以下
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