Usually, age is determined by physical characteristics, such as teeth or bones.

通常说来，年龄是通过生理特征确定的，譬如牙齿或骨骼。

youdao

A protective covering, structure, or organ of an animal or a plant, such as teeth, claws, thorns, or the shell of a turtle.

防御器官动物或植物的防护层，结构或器官，如牙齿，爪子，荆棘或乌龟的壳。

youdao

First, the defensive posture, where the body is fluffed up to appear larger or weapons such as teeth and claws are flashed.

首先是防御姿态，如果身体上有羽毛的话就竖起来，或是亮出牙齿和爪子等武器。

youdao

In April 2010 Chestnut was sued by a former investor who alleged fraud and accused Plummer of using investors' money for such things as porcelain teeth veneers, a Lexus SUV for his wife and membership at Dallas' Canyon Creek Country Club.

FORBES: Magazine Article

With the comfort of permanent agricultural settlements came uncomfortable new scourges such as intestinal parasites, bad teeth and the fouling of the water supply.

ECONOMIST: Food in history

Other harsh ceremonies, such as circumcision without anesthetic, teeth sharpening, and physical disfiguration, make what I suggest individual investors endure seem like a tiptoe through the tulips by comparison.

FORBES: Investor Rites of Passage - Part 1