A:甲、乙两车都做匀速直线运动
B:甲车的速度为10m/s,乙车的速度为2m/s
C:经过6s,甲、乙两车相距2m
D:经过5s,甲、乙两车通过的路程均为10m
Though _______ time, he managed to finish the task on time.
Water is very dangerous sometimes. So we must be careful ______ it.
为了保持天平测量精确,使用时不能超过____ ,并保持天平干燥、清洁.