如果向北走10m记作+10m，那么向南走15m记作______m．
“向北”和“向南”相反，若规定向北走10m记作+10m，则向南走15m记作-15m．
--- What do people wear when they go to the theatre?
--- Well, it isn’t very . People can wear anything they like.
A．formal
B．certain
C．modern
D．simple
利多卡因消除单向传导阻滞是因为
A．促进Na+内流B．促进K+外流C．抑制Na+内流D．抑制Ca2+内流E．抑制K+内流
