normal chordal tooth thickness

例句：

1. 1. The normal temperature for a human body is 98.6 degrees Fahrenheit.
   人体正常体温是98.6华氏度。
2. 2.The normal course of the disease was to progress slowly.
   这种疾病的通常进程是缓慢进展的。
3. 3.The normal distribution of income in a society is an important factor in economic development.
   一个社会中收入的正常分布是经济发展的一个重要因素。