Today,computers are really helpful. They           everywhere.

已知:线段OA⊥OB,点C为OB中点,D为线段OA上一点.连接AC,BD交于点P.
(3)如图3,把题目中“点C为OB中点”改为“BC:CO=1:n”,当AD:DO=1:m时,求的值.

解题思路:类比第1题,第2题,过点D作DE∥OB交AC于点E,则AE和CE的数量关系是        ,EP和CP的数量关系是        ,的值是        .以上横线处,依次所填正确的是(    )

已知:线段OA⊥OB,点C为OB中点,D为线段OA上一点.连接AC,BD交于点P.
(2)如图2,当AD:DO=1:m时,求的值;

解题思路:类比第1题,过点D作DE∥OB交AC于点E,则AE和CE的数量关系是        ,EP和CP的数量关系是        ,的值是        .以上横线处,依次所填正确的是(    )

已知:线段OA⊥OB,点C为OB中点,D为线段OA上一点.连接AC,BD交于点P.
(1)如图1,当D为OA中点时,求的值;

解题思路:(1)尝试探究:在图1中,过点D作DE∥OB交AC于点E,则AE和CE的数量关系是        ,EP和CP的数量关系是        ,的值是        .以上横线处,依次所填正确的是(    )

—How about swimming in the river with us?
—      . My parents often tell me not to do that.

—Why not join us in the game,Nancy?
—      ,but I have to do the dishes today.

—What about going hiking this Sunday?
—      . I’d like to go with you.

—What about       hiking this Sunday?
—Great. I’d like        with you.

—It’s very hot outside.
—Why       you stay at home?

—Hello, Jack. How are you doing?
—      .