RNA聚合酶中识别模板转录起始部位的亚基是
A.原核RNA聚合酶亚基δB.原核RNA聚合酶亚基αC.原核RNA聚合酶亚基βD.原核RNA聚合酶亚基σ
参考答案:D
--Would you mind ________ my pet dog while I'm away?
-- Sure, no problem. [ ]
A. setting up
B. looking after
C. turning down
D. keeping out
桩的直径一般为根直径的
A.1/4B.1/3C.2/3D.1/5E.1/2