Now, there are genes that promote normal cell growth called proto-oncogenes.

这时，有一些促进正常细胞生长的基因被称作原癌基因。

Research has shown that certain minerals are required by plants for normal growth and development.

研究表明，某些矿物质是植物正常生长发育所必需的。

Researchers found that during normal hair growth the cells continually pivot between compartments of the developing hair follicle.

研究人员发现，在正常的毛发生长过程中，细胞不断在发育中的毛囊室之间转移。

The relative balance maintained between generation and restriction ensures normal growth and development.

相生和相克之间达到平衡才能保证正常的生长和发展。

It hurts, and there is that blurry line sometimes between, Am I harming myself or is this normal growth?

很痛，有时界限很模糊，我是在伤害自己还是这是正常的成长？

Primary amenorrhea is when a female hasn't had her first menstruation, called menarche, by age 16, despite normal growth and having started puberty.

原发性闭经指女性在16周岁前没有初次月经（即初潮），尽管生长发育、进入青春期均无异常。

A 1928 study in the American Journal of Diseases of Children found that when very young normal children were given free access to a variety of natural foods to choose by themselves; they selected foods that facilitated normal growth and development.

1928 年《美国儿童疾病杂志》上的一项研究发现，当非常年幼的普通儿童可以自主选择各种天然食物时；他们往往选择那些能促进正常生长发育的食物。