单词：acid etching of tooth surface
单词：acid etching of tooth surface 相关文章
This is Scientific American's 60-Second Science. I'm Karen Hopkin. This will just take a minute. Beauty is only skin deep. And the beauty of shiny white teeth is even less deep. Because a new study shows that fluoride forms a thinner protective shiel
Scientific American(十二)月
Flawless pearls are among the most symmetrical spheres biological organs. But do they get so round? Turns out they turn. Pearls and mollusks such as oysters create so-called pearls acs around intrusive pieces of grit. The sac coat the yelten with the
Scientific American(六)月
Did you know that there could be more bacteria living in your mouth than there are people on earth? 你知道吗，寄居于你口中的细菌有可能比全世界的人口数还多？ Bacteria love our mouths because the livin is easytheres plenty o
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[00:02.81]Unit 21 Human Biology Lesson 1 Chewing Gum [00:09.19]TO CHEW OR NOT TO CHEW... [00:12.21]Diet specialists regularly inform us [00:14.82]that it is important to chew our food properly. [00:17.74]They suggest that if we chew our food [00:19.7
北师大版高中英语模块7(选修)
This is the VOA Special English Health Report. It might seem hard to imagine that a bad tooth could be deadly. More than 41,000 students in the Philippines brushed their teeth at the same time last month to set a world record, organizers said. The r
VOA慢速英语2007年（三）月
Getting Rid Of Cavities 牙痛是继续忍受还是提前做好防护?爱护牙齿，每天的必修课。 M:Sorry,I'm late.I was brushing my teeth. W:Brushing your teeth?Right before 'A Moment Of Science'? Why? M:I'm trying to get rid of a cavity. W
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