【单选题】依地酸二钠钙(CaNa 2 EDTA)()
A.
是最常见的氨羧螯合剂,可与多种金属形成稳定可溶的金属螯合物排出体外
B.
化学结构、作用与依地酸相似,但促排铅的效果比依地酸好
C.
为含有活性巯基(-SH)化合物,药物进入体内后可与某些金属形成无毒的、难解离的螯合物由尿排出
E.
主要用于治疗锑、铅、汞、砷、铜等中毒。近来发现用该药口服治疗铅中毒有效
【单选题】测定灰分取样时,应以灼烧后得到的灰分量为 来决定取样量
【单选题】What is Pre-Cana?
A.
It is used to reduce the divorce rate of all couples.
B.
It is a form of premarital counseling for Catholics.
C.
It is a course for all couples undergoing before marriage.
D.
It is the only reason that Catholics have the lowest divorce rate.
【简答题】传动系统有哪些总成组成?叉车传动系统有哪些传动方式?
【简答题】过氧化氢俗名双氧水,分子中含有氧氧非极性共价键,医疗上可作外科消毒剂.试回答下列问题: (1)H 2 O 2 的电子式是______.过氧化氢分子中氧原子的基态原子核外电子排布式______. (2)将双氧水加入经酸化的KMnO 4 溶液中,溶液的紫红色消褪了,此时双氧水表现出______性. (3)实验室用双氧水制取氧气时常加入二氧化锰,该反应的化学方程式为______. (4)过氧化氢具有漂白...
【简答题】水玻璃的化学组成是什么?水玻璃的模数、密度(浓度)对水玻璃的性能有什么影响?
【单选题】According to the author, the safety net can
B.
relieve the pressure that comes with old age.
C.
lead to a shrinking workforce.
D.
have some negative effects on the economy.
【简答题】What is the first sign that Jesus reveals in Cana of Galilee?
【判断题】d t和 zh chi shi的发音部位比较接近。