"We have already known its work mechanism now

Beat to whet by one is own
"Organic material layer the weak link that is in the whole chain, " the uncle of Ji Er says especially that"some in sea urchin tooth in advance make sure to well break a point, with beat the principle likeness of bore paper, the hard crystal will break a point to shed off at these."
Strong and tough layer bluntness once changing, will weakly break to order nature to shed off at these, the lately sharp crystal layer will expose and promise thus the sea urchin tooth is placed in sharp status forever and be like the nail don,t stop to grow.
Study achievement is announced by the lately 《American chemistry academic association magazine 》 double weekly magazine.
"We have already known its work mechanism now, " the uncle of Ji Er says especially that"making use of these knowledge can develop in the process of using in can carry on ego to beat grinding tool."