11.5 be going to / will

11.5 be going to / will
         
用于条件句时， be going to　表将来
　　　　　　　              will　表意愿
　　If you are going to make a journey, you'd better get ready for it as soon as possible.
　　Now if you will take off your clothes, we will fit the new clothes on you in front of the mirror.