首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Medicine comes in many forms. In its liquid form, medicine affects the body very quickly. But the effects of liquid medicine arc
Medicine comes in many forms. In its liquid form, medicine affects the body very quickly. But the effects of liquid medicine arc
admin
2011-03-01
70
问题
Medicine comes in many forms. In its liquid form, medicine affects the body very quickly. But the effects of liquid medicine arch’ t usually long-lasting. This is why pills and capsules (胶囊) are also used.
The pills and capsules being sold today arch’ t perfect, either. Pills dissolve in the stomach. The medicine in the pills is released when the pills dissolve. But often, the pills dissolve too quickly.
Scientists have been trying to develop a pill that can release medicine slowly over a long period of time. They have applied their knowledge of plants to produce the "osmotic (渗透的) pump pill".
The cell walls of plants are made of cellulose (纤维素). Cellulose is a very porous substance. Their holes are big enough to allow water through the cell walls. As water enters a cell, pressure builds up in the cell. The pressure pumps other substances out of the cell. These substances leave the cell through the cellulose wall. This slow, steady process is called osmosis.
The osmotic pump pill is coated with synthetic cellulose. Liquid medicine is contained in the pill. The holes in the cellulose coating of the pill are big enough to allow water in the pill. As water from the body enters the pill, pressure builds up in the pill. The medicine is then slowly pumped out of the pill.
The way that the osmotic pump pill works is based on a process called______.
选项
A、synthesis
B、pressure
C、cellulose
D、osmosis
答案
D
解析
从第四段最后一句可知答案。
转载请注明原文地址:https://kaotiyun.com/show/lLjd777K
本试题收录于:
公共英语三级笔试题库公共英语(PETS)分类
0
公共英语三级笔试
公共英语(PETS)
相关试题推荐
Whatarethesepeopleplanningtodo?
Whatarethesepeopleplanningtodo?
Whatarethesepeopleplanningtodo?
Geographyisthestudyoftherelationshipbetweenpeopleandland.Geographerscompareandcontrast【C1】______placesontheeart
Geographyisthestudyoftherelationshipbetweenpeopleandland.Geographerscompareandcontrast【C1】______placesontheeart
CustomsofficersataLondonairportyesterdayfound$500,000worthofdrugswhichwerebeingsmuggled(走私)intoBritaininboxes
Largeanimalslivinginthedeserthavedevelopedanumberofadaptationsforreducingtheeffectsofextremeheat.Oneadaptati
Writeanessayofabout120wordsentitled"DoesTVmakeoursocietybetterorworse?"Listsomepositiveandnegativeeffectso
Blinkscantakeseveralforms.Besidestheblinksthatwashtheeye,therearethoseassociatedwithunexpectedcircumstances(s
随机试题
据美国发现频道报道,几家宇航公司正在进行一项试验,试图在1998年11月9日向太空发射一个叫做“进步号”的“大镜子”,在夜晚把光明带给世界上任何一个需要它的城市。这面大镜子反射的太阳光比满月时的光大约亮十倍。这面“大镜子”其实是用镀铝的聚酯薄膜做的
生产医疗器械应当符合__复核的注册产品标准
根据《中华人民共和国海关法》的规定,进出口货物的纳税义务人,应当()缴纳税款。
运用存货模式确定现金最佳持有量时,其中的转换成本相当于存货管理中的()。
对于宽泛型的薪酬等级,主要的特点是薪酬等级少、成平行型。这种等级类型在()、业务灵活性强的企业中常见。
“因材施教”要求教育必须符合人类发展的()。
()可以依法对公民的通信内容进行检查。
元朝时期,制定出《授时历》的天文学家是()。
知觉恒常性【首都师范大学2011;四川大学2014】
DietingadvisorDr.RobertAtkinsrecommendseatingadiethighinproteinforthosewhowanttoloseweightandkeepitoff.Th
最新回复
(
0
)