Lisa has to undergo an amputation of his right leg above the knee, to prevent dreading of cancer to other parts of his body.(what do you understand by word amputation in the above sentence?)​

is basically a good source of getting and others by what you know for example if someone asked a question and you know the answer you could answer it and get some points or if you need on a question you could make a post about it and wait till someone answers it or just look up the question and see if someone else has asked about it