如果向北走20米记为是+20米，那么向南走70米记为（ ）米．
﹣70
旋转阳极X线管定子的极数一般是
A．5
B．4
C．3
D．2
E．1
You can ______ this car with that one; then you will see which one is better.
A．match
B．share
C．compare
D．measure
