严禁在()的情况下盲目施救。
参考答案:未采取防护措施
Using Chebyshev's inequality, what is the minimum proportion of observations from a population of 500 that lies within two standard deviations of the mean, regardless of the shape of the distribution()
A. 75%.
B. 89%.
C. 99%.
初期龋的变化不包括
A.硬组织发生脱矿
B.微晶结构改变
C.牙齿透明度下降
D.牙釉质呈自垩色
E.牙釉质出现洞