[单选题]
You are traveling at 55 mi/h in the +x axis rb:u:sfz.i4 cx):qtclel i wa9 lk9. b5elative to :o25 .l1jafhwo kl*am s9jfv 6d,dik1a straight, level road and pass a car traveling at 45 mi/h. The relative velocikma1 j2l*vh69 :ifo, foaw5k j1.d lsdty of your car to the other car is