A:t1时刻甲车从后面追上乙车
B:t1时刻两车相距最远
C:t1时刻两车的速度刚好相等
D:从0时刻到t1时刻的时间内,两车的平均速度相等
—________ great fun we had at the party last night!
—Yes, it was so exciting that everyone was happy.
在呼吸时不能进行的生理活动是( )