He ______ his bike so he has to walk there. [ ]
A. lost
B. has lost
C. had lost
D. loses
答案:B
位于外踝高点与跟腱之间凹陷中的腧穴是
A.委中
B.委阳
C.昆仑
D.承山
E.飞扬
潜油泵加油机的安装必须配备安全阀,安全阀与输油管道的连接采用不锈钢波纹管,安全阀应安装于固定水泥基础的角钢上,并与上下管连接,安全阀与角钢连接应牢固。