题目内容

大肠杆菌染色体的分子质量大约是2.5×109Da,核苷酸的平均分子质量是330Da,两个邻近核苷酸对之间的距离是0.34nm,双螺旋每一转的高度(即螺距)是3.4nm,请问:

查看答案
更多问题

1t wasn't such a good dinner ____________ she had promised us.
[A] that
[B] which
[C] as
[D] what

[A] evolved
[B] enclosed
[C] engaged
[D] involved

Which of the following best states the theme of the passage?
[A] There is no good news on AIDS.
[B] The total economic cost for AIDS patients is staggering.
[C] Nationwide efforts must be made to find a cure for AIDS.
[D] AIDS has a deep impact on American society

假定你从一新发现的病毒中提取了核酸。请用最简单的方法确定:①它是DNA还是RNA?②它是单链还是双链?

答案查题题库