【简答题】Stroke中风 risk factors are determined by ______, lifestyle, and sometimes the environment.
【单选题】What is the major risk factor for stroke?
D.
Family history of stroke
【判断题】一个好的策略是找到一个非形式的证明然后试着形式化它。
【简答题】Some people can reduce their risk of stroke if they______.
【单选题】比较两种疗法对乳腺癌的疗效,首先根据患者年龄将120例患者配成60对,再将每个对子内的2名患者随机分为两组分别采用两种方法治疗。该随机化方法为: