A:﹣2
B:0
C:2
D:±2
一汽车以108 km/h的速度沿一长直的高速公路行驶,试求站在路旁的人观察到该汽车长度缩短了多少?已知此汽车停在路旁时,测得其长度为3 m.
There was a time ________ the boy often quarreled with his parents.