凡用停车信号防护的施工点,在停车信号拆除后,列车需减低速度通过施工地点时,应按()防护办法防护。
A.移动停车信号;
B.手信号;
C.减速信号;
D.应急信号
参考答案:C
周围血中还原血红蛋白浓度为多少时出现发绀()
A.>20g/L
B.>30g/L
C.>50g/L
D.>70g/L
E.>100g/L
Later in this chapter cases will be introduced to readers _____ consumer complaints have resulted in changes
in the law. [ ]
A. where
B. when
C. who
D. which