国家实施经济调控并不直接干预企业微观经济的运行,这是指经济调控手段的哪一特点( )
A.通过市场机制起作用 B.间接性C.非歧视性 D.非强制性
参考答案:B
Only after spending several nights working on the math problem to wonder whether the problem was wrongly set.
A.had he begun
B.he began
C.did he begin
D.began he
请指出在oriC或ΦX型起点起始的DNA复制之间存在的重要差异。