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| As you probably know from the appeals being made for funds to fight cancer and from all the research that is being done 1 this subject- cancer is a great threat to the health and life of mankind. We will only discuss cancer in general 2 , so you can have an idea of what 3 in a body that has cancer. A cancer is a continuous growth in the body which doesn't follow the normal growth 4 . The cells 5 the cancer spread through the body to parts which may be 6 the spot where the cancer begins. 7 it is removed or destroyed the cancer can 8 the death of the person. Cells in the body are growing 9 . As they wear 10 and disappear, their places are 11 by new cells of exactly the same kind. But cancer cells look and act 12 from normal body cells. When these cancer cells divide and increase in 13 , they don't change into the fully grown form and then stop reproducing. 14 they remain young cells and continue to reproduce in number until they are harmful. As the cancer cells grow, they do not 15 in one spot, but separate and move in 16 the normal cells. They may become so 17 that the normal cells in this part of the body cannot continue to work or even remain alive. When the cancer 18 into the blood, it is carried to distant parts of the body. 19 it may grow to form large masses which interfere (干扰) with the activities of the 20 cells. | ||||
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