① ____          ② ____           

③ ____       ④ ____          

 ⑤ ____        ⑥ ____  

如图，矩形ABCD的对角线AC和BD相交于点O，过点O的直线分别交AD和BC于点E、F，AB=2，BC=3，则图中阴影部分的面积为（　　）

为了测量某一轻质弹簧的劲度系数．把该轻质弹簧一端固定，用大小为F₁的力压弹簧的另一端，平衡时长度为l₁；改用大小为F₂的力拉弹簧，平衡时长度为l₂．弹簧的拉伸或压缩均在弹性限度内，则该弹簧的劲度系数是____．

    My mother is a teacher. On weekdays, she gives lessons at school and on Saturdays she works in clubs. On Sundays, she is still busy.

On Sunday morning, mum gets up at six. She cooks breakfast for us first. And then it's time for cleaning. After that, she has breakfast with father and me. At 9, she goes to buy food for lunch in the supermarket. She can have a short rest after lunch. In the afternoon, mum doesn't go out. She helps me with my lessons. She does some reading, too.

    Mother watches TV at about 7 when she finishes (完成) the housework. But at that time she is always tired and falls asleep (睡着) in the sofa sometimes.