诊断再生障碍性贫血的主要检查是

A．临床表现

B．一般实验室检查

C．磁共振成像(MR

D．骨髓检查和活检

E．同位素扫描

If you keep still, you may sit ____ this end of the boat ____ the other. [ ]

A. both; and

B. either; or

C. neither; nor

D. not; but