A:一定显酸性
B:一定显碱性
C:可能显酸性或碱性,也可能显中性
D:可能显中性
⑴How old are you?____ A. Thank you.
⑵This is for you.____ B. Yes, it is.
⑶Don't shout here.____ C. I'm six.
⑷Where's my schoolbag?____ D. I'm sorry.
⑸Is that your pencil?____ E. It's under the desk.
汽车甲沿着平直公路以速度v 做匀速直线运动,当它路过某处的同时,该处有一辆汽车乙开始做初速度为零的匀加速直线运动去追赶甲车,根据上述已知条件( )