Jake’s son Simon, aged 16, wished to buy a particular hi-fi system which had just been launched on the market. He decided to save up some more money and purchase it during the coming months. Jake decided to surprise his son and bought a system from Martin. Martin assured Jake this was the latest model. However, much to Simon’s dismay the model his father purchased was the 2008 model.Required:

(b) Explain whether it is possible for Jake to claim invalidity of contract and on what grounds. (6 marks)

关于渐变工具（Gradient Tool）的使用，下列哪些说法是正确的？（）

A.渐变工具不但可以改变渐变的方向也可以改变图形中渐变颜色的分布

B.放射状渐变是以一点为圆心向外扩散的一种渐变方式，扩散方式可以通过渐变角度控制来得到改变

C.使用渐变工具拖曳渐变色时，如果要让渐变的方向为水平、垂直或者45°角的倍数的方向，在拖拉鼠标的同时需要按住Command（MaC./Ctrl（Win）键

D.如果渐变类型为放射状渐变，使用渐变工具确定渐变的中心点，该方法可以非常方便地制作高光球体