我试试看,不是做广告,您也可以自己找类似的,小孩子觉得好玩有挑战就行
1。This is not a maths book(易)
2.This is not another maths book(易)
3.the original area mazes(梯度)
4.Can you solve my problems?(较难)
5.Things to make and do in the fourth dimension(难)