【答案】:D
初生时由于产程的刺激及体内外环境的突然变化,白细胞计数为(15~20)×10
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/9825bc315c6034a84cc8f516d91349540923767a?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
/L(1.5~2万/mm
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/bd315c6034a85edf9ea6b3b45b540923dd54757a?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
),生后6~12小时由于血液浓缩,计数可增高到(21~28)×10
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/35a85edf8db1cb135c437184cf54564e92584b7a?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
/L(21~28万/mm
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/ca1349540923dd544e59eaffc309b3de9c82487a?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
),一周岁平均12×10
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/dc54564e9258d109a8c9e425c358ccbf6c814d7a?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
/L(1.2万/mm
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/574e9258d109b3de8095a9ffdebf6c81800a4c7a?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
),婴儿时期10×10
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/b2de9c82d158ccbf7396f8ad0bd8bc3eb135417a?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
/L(1万/mm
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/6d81800a19d8bc3e92224b5d908ba61ea8d3457a?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
)左右,8岁时接近成人水平。白细胞分类计数,不同年龄差别很大,主要为粒细胞同淋巴细胞比例变化,初生时中性粒细胞占60%~65%;淋巴细胞占30%~35%,生后4~6天两者比例相等,出现第一次交叉,以后在整个婴儿期,学龄前期,中性粒细胞渐增加,4~6岁时,两者比例又相等,形成第二次交叉。7岁后两者的比例与成人相似。故本题答案为D。