除哪项疾病外其他引起便秘的原因可通过直肠指诊诊断（）。
A.直肠癌
B.肛裂
C.坚硬粪块堵塞
D.痔疮
E.结肠癌
参考答案：E
The students in China often get to school _____ bike, but the students in Japan usually _____ the train to school.
A．on ; get
B．by ; take
C．in ; with
D．ride; in
无脉冲拨号或双音频拨号一般是其信号输入电路故障。
