A:①②
B:③④
C:①③
D:①②③④
____
Peter:Have some water.
Li Yan:Thank you,Peter.
Peter:Do you like coffee?
Li Yan:No,I don't.I like water and juice.What about you?
Peter:I like water and coffee.
学校到县城有28千米,全程需1小时,除乘汽车外,还需要步行一段路,已知汽车的速度为36千米/时,人步行的速度为4千米/时,则步行用了( )