个数

The wordwrap() function wraps a string into new lines when it reaches a specific length.

符串按符数换行。

The uniformity of chloroplast grana lamellae,, the numbers and cristae of mitochondria, and the concentration of nucleus karyolymph were different among different mature grade leaves.

不同成熟度叶片超微结构变化明显，主要表现在叶绿体片层结构整齐程度、线粒体数和嵴数以及细核核液浓度上。

We will be concerned primarily with bijective proofs, i.e., showing that two sets have the same number of elements by exhibiting a bijection (one-to-one correspondence) between them.

我们主要关心的是对射的证明，也就是透过在两集合间建立一对射（一对一且映成的函数）来证明它们的数相等。