主页
学科
搜索
账户
常见问题
当前学科：基础生命科学
题目：
单选
一个核苷酸单体戊糖5’位碳的磷酸与另一个核苷酸单体戊糖第3’位碳相连，形成3’、5’-（）。
A . 磷酸二酯键
B . 离子键
C . 肽键
答案：
<查看本题扣1积分>
查看答案
答案不对？请尝试站内搜索
推荐知识点:
重症哮喘发作时，为缓解支气管痉挛可用()
简述本作业指导书包含了哪些内容？
以下关于构件的堆放高度说法正确的是（）。
男，67岁，肺癌术后3个月，自觉全身多处骨骼疼痛。X线检查，胸、背部和腰部骨骼未见明显异常。如果上述检查均证实患者存在肿瘤骨转移，疼痛难以控制，骨转移灶放射性浓聚明显，为了缓解骨痛和治疗骨转移灶，可考虑选择下列哪项核素治疗（）
The task of being accepted and enrolled(招收)in a university begins early for some students. Long【C1】______they graduate from high school. These students take special【C2】______to prepare for advanced study. They may also take one of more examinations that test how【C3】______prepared they are for the university. In the final year of high school, they【C4】______applications and send them, with their student records, to the universities which they hope to【C5】______. Some high school students may be【C6】______to have an interview with representatives of the university: Nearly【C7】______, and usually very frightened, they are【C8】______to show that they have a good attitude and the【C9】______to succeed. When the new students are finally【C10】______, there may be one more step they have to【C11】______before registering for classes and【C12】______to work. Many colleges and universities【C13】______an orientation(情况介绍)program for new students.【C14】______these programs, the young people get to know the【C15】______for registration and student advising, university rules, the【C16】______of the library all the other【C17】______services of the college or university. Beginning a new life in a new place can be very【C18】______. The more knowledge students have【C19】______the school, the easier it will be for them to【C20】______to the new environment. However, it takes time to get used to college life.【C1】A．asB．afterC．sinceD．before
控制文件柜5VDC电源调节器提供（）的电源
什么叫雷电电磁脉冲？它对电子信息系统有什么危害？对雷电电磁脉冲有哪些防护措施？
为了更好地配合训练和最大限度的发挥运动能力，运动员的膳食应适时进行调整，满足不同时期和不同项目运动员的营养需要。力量项目运动员应适当增加摄入（）。
在国家预算中，单式预算是指（）。
（）指按照规定具体抗配和封装公文。