第三部分：概括大意与完成句子(第23~30题，每题1分，共8分)
下面的短文后有2项测试任务：(1)第23～26题要求从所给的6个选项中为第1~4 段每段选择1个最佳标题；(2)第27～30题要求从所给的6个选项中为每个句子确定1个最佳选项。
Cancer
1. Cancer is a group of many related diseases that begin in cells, the body's basic building blocks. The body is made up of many types if cells normally, cells
23. Paragraph 1
24. Paragraph 2
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A. Does cancer always cause pain?
B. Can cancer be prevented?
C. What is cancer?
D. How common is cancer?
E. What causes cancer?
F. How is cancer treated?
27. Cancer occurs when cells in the body divide without
28. Gene alterations may be caused by
29. Treatment for cancer may also bring about some
30. Cancer patients may differ in their
A. prescription medicines
B. control or order
C. tolerance for pain
D. various factors
E. different genes
F. side effects