Exactly when the so - called " pain pathways " in the brain begin to develop is not certain but scientists estimate between weeks 23 and 30 严格地说，人们对于所谓的“疼痛路径”是何时在大脑中开始发育的并不十分清楚。但据科学家估计，应该是在第23周至30周。
They often become thirsty , which drives them to drink large amounts of water and , consequently , to urinate a great deal ; they also start slobbering and drooling 病如其名，遭感染的鹿只在数周至数月间体重降低，通常会变得十分口渴，大量喝水并大量排尿，也会开始流口水。
Watch at least one wholesome , funny show a week . laughing produces feel - good endorphins in your body that help ward off disease . and laughing keeps you optimistic 每一周至少观看一场健康的、有趣的演出，欢笑会在你的体内产生出感觉良好的内啡肽，这会帮助你抵御疾病，而且欢笑还会让你保持乐观。
" my invention , " joe said proudly . " beats a washboard an your knuckles , and , besides , it saves at least fifteen minutes in the week , an fifteen minutes ain t to be sneezed at in this shebang . “我的发明， ”乔骄傲地说， “比搓衣板和你的手指头强多了，一周至少能省十五分钟，干这种活能省计五分钟就不可小看了。 ”
Recordings are stored in first in first out basis , thus assuring perpetual recording without replacing cf card . the length of period recordings are stored within the microlog is dependent on the frequency of calls and cf cards storage size 不需更换任何录音组件，录音循环储存，依记忆卡容量及通话频率， ?录音在机内可保留数周至数月以上。
There is no clear boundary and accurate forest area defined for the village and they have never issued the forestry certificate to the administrative village or to individual farmer except on land conversion land 周至县没有规定村庄的清楚边界，也没有精确界定属于村庄的森林区域，并且除了土地转换许可外，他们从未向行政村或者个体农民签发林业经营执照。
With the support of the several theories about the tourist market discussed in the text , the author tries to put forward a frame of tourist market planning which directs the general planning of the ecosystem preserving and tourism developing of the southern taibai mountain 在各种理论的支撑下，本文试图提出一个新的旅游客源市场分析框架，并将之应用于南太白山(周至)生态保护与旅游发展总体规划的实际项目。
The number of cgrp positive cells declined in postnatal rat lungs . a significant difference was seen between groups of 20 - day fetuses and 1 - day rats and groups of 1 - day and 1 week rats . cgrp positive cells in groups after 7 - day rats were very limit and no significant difference in these groups 生后阳性细胞数量减少，胚20日与生后1日、生后1日与1周组间差异显著( p 0 . 01 ) ，生后1周至18月龄各组细胞数量很少，组间无统计学差异( p 0 . 05 ) 。
