Ben and Jim are twin brothers. They are nine. They are pupils. They study in Yuxin Primary School. They are in the same class. Everyday they go to school and come back together.

    Their teacher, Mrs. Green, says to the pupils. Please write a composition (作文) 'My Mother'.

    Jim is a good boy. He writes the composition at home. But Ben plays football with his friends. The next day Mrs Green says to the class, “I read your compositions today. But two of yours are just the same.” Ben stands up and says, “Jim and I are twins. We have the same mother.”

如图1,在平面直角坐标系中,有一矩形ABCD,其三个顶点的坐标分别为A（2,0）、B（8,0）、C（8,3）．将直线l:y＝－3x－3以每秒3个单位的速度向右运动,设运动时间为t秒．

（1）当t＝_________时,直线l经过点A．（直接填写答案）
（2）设直线l扫过矩形ABCD的面积为S,试求S＞0时S与t的函数关系式．
（3）在第一象限有一半径为3、且与两坐标轴恰好都相切的⊙M,在直线l出发的同时,⊙M以每秒2个单位的速度向右运动,如图2所示,则当t为何值时,直线l与⊙M相切？

俗话说：半大小子，气死老子。许多家长抱怨说，孩子进入初中后特别不听话，叫他向东他向西，让他不干他非要干。孩子这种心理属于（    ）