题目

   If you spent years training to be a lawyer and had a great steady income,would you leave it to undertake a silly plan that only your mum and girlfriend believed in? That’s exactly what Tom Pakenhamdid.    He had the idea of starting an eco-friendly taxi company and so with five environmentally-friendly cars Green Tomato Cars was born. Now,only a few years later,the company has a group of 60 Toyota Prius Hybrids.    When the company started in 2006 Tom admits,”Only my mum,girlfriend Sophie,now my wife,and Jonny(his business partner) were 100 percent behind the idea of start若=（2，2），=（2，2）则与的夹角θ等于A．300B．450 C．600D．750