单项选择题

A．About ten years.
B．About two years.
C．About twenty years.
D．About thirteen years.
<上一题 目录 下一题>
热门 试题

填空题
low
单项选择题
A．A certain chemical in their bodies.B．The change of certain circumstances around them.C．A certain temperature.D．A certain season in the year.
A．A certain chemical in their bodies.
B．The change of certain circumstances around them.
C．A certain temperature.
D．A certain season in the year.
相关试题