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<p style="color:#333333;font-weight:normal;font-size:16px;line-height:30px;font-family:Helvetica,Arial,sans-serif;hyphens:auto;text-align:justify;" data-flag="normal">文中文献：</p><span><br></span><p style="font-size:16px;line-height:30px;font-family:Helvetica, Arial, sans-serif;color:#333333;font-weight:normal;text-align:justify;" data-flag="normal">1.图为 B细胞的演化过程。 B细胞利用其表面的抗体搜捕入侵者。自然会选择与入侵者的部分结合能力最强的 B细胞，使其不断复制。</p><p style="font-size:16px;line-height:30px;font-family:Helvetica, Arial, sans-serif;color:#333333;font-weight:normal;text-align:justify;" data-flag="normal"><img data-key="0" src="http://imagev2.xmcdn.com/storages/2988-audiofreehighqps/82/0E/GKwRIJEFq0fWAAE8iQEKU-11.jpg!op_type=4&device_type=ios&upload_type=attachment&name=mobile_large" alt="" data-origin="http://imagev2.xmcdn.com/storages/2988-audiofreehighqps/82/0E/GKwRIJEFq0fWAAE8iQEKU-11.jpg?op_type=0" data-large="http://imagev2.xmcdn.com/storages/2988-audiofreehighqps/82/0E/GKwRIJEFq0fWAAE8iQEKU-1...