低钾血症时肌无力为最早表现，一般先出现躯干肌软弱无力，以后延及四肢和呼吸肌。()
参考答案：错
如何用平晶检定外径千分尺测量面的平面度和平行度？
There _____ a hotel, a school, a post office and two markets on this street.[ ]
A. is
B. are
C. have
D. has
