红富士苹果成熟后由青变红，并且酸甜可口，与此相关的细胞结构是[ ]
A．叶绿体
B．线粒体
C．液泡
D．内质网
答案：C
A left-luggage office is a place where bags ______ be left for a short time, especially at a railway station.
A．should
B．can
C．must
D．will
发动机怠速工况
A left-luggage office is a place where bags ______ be left for a short time, especially at a railway station.