Remember! When you write your introduction do not copy phrases from the task. Sometimes students can't think of a better way to express what they want or simply find it easier to copy part of the task. Copying an exact phrase is not the solution, however! You will be penalized for doing so.... so please, please, avoid it at all costs.
Let's take for example the beginning of the previous task: "Online shopping has been growing exponentially...." Copying 'online shopping' is acceptable but the rest should be rephrased. There are numerous ways of doing this: Online shopping 'has increased dramatically', 'has doubled in the last decade', 'is becoming more and more frequent' etc. Under no circumstances do we repeat 'growing exponentially' no matter how 'perfect' it sounds. Post a comment if you have any questions and I hope this is helpful! :)