在细菌转录中，使RNA聚合酶与DNA启动子牢固结合的关键因子是( )。
A．α2 B．ββ’ C．α2ββ’ D．σ
参考答案：A
I would have come earlier, but I _____ that you were waiting for me. [ ]
A. didn't know
B. hadn't known
C. would have known
D. haven't known
刑事诉讼参与人中，不属于其他诉讼参与人的是( )
A．法定代理人和诉讼代理人B．当事人C．辩护人和证人D．鉴定人和翻译人员
