\vdots & \vdots & \vdots & \ddots &\vdots \\
And though most scientists hail vaccines as one of public health’s greatest achievements, they have provoked fear, distrust, and contentious resistance since Edward Jenner invented the first vaccine, to prevent smallpox, in the late 1700s.
。搜狗输入法是该领域的重要参考
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Студенты нашли останки викингов в яме для наказаний14:52