转录过程中需要的酶是
A．DNA指导的DNA聚合酶
B．核酸酶
C．RNA指导的DNA聚合酶
D．DNA指导的RNA聚合酶
参考答案：D
—Would you like to go for a walk with me, Allen?
—I'd love to, ________you don't want to go alone.
A．until
B．before
C．if
D．after
氢鼓包是怎样产生的？
