电阻R1=6欧姆，与电阻R2串联后的总电阻是18欧姆，那么R1与R2并联后的总电阻为（）。
A、12欧姆
B、8欧姆
C、4欧姆
D、2欧姆
参考答案：C
核糖体结合序列(RBS)
A．也叫Pfibnow盒B．在mRNA分子上C．由Meselson-Stahl首先发现D．真核生物转录起点
Which of the following is NOT a recommended procedure for compliance with the Standards of Professional Conduct relating to misrepresentation The firm:（）
A. specifically designates which employees are authorized to speak on behalf of the firm.
B. discontinues using the work completed by a former member or candidate.
C. provides a written list of the firm's available services and a description of
the firm's qualification.
