画出一个只有2条对称轴的四边形．
根据轴对称的定义可知，四边形中长方形只有2条对称轴，如右图所示．
Amy finishes _____ her homework before 9 p.m every day. [ ]
A. to do
B. doing
C. does
GK1C机车启动时曲轴转动但不发火的原因有哪些？
