直肠触诊触及质地坚硬、表面凸凹不平的包块，应考虑的是( )
A．直肠息肉B．肛裂C．直肠癌D．直肠周围脓肿E．直肠炎
参考答案：C
一Do you know ____________ the MP4 yesterday?
一 Sorry，I’ve no idea about it.[ ]
A. how much did he pay for
B. how much he paid for
C. he paid for how much
D. he paid how much for
过滤器发生脏堵后，表面可能产生（）；（）；（）等现象
