____ sister is a nurse. What about your sister? (My; Your)
老师把刚刚制备的痢疾杆菌装片与酵母菌装片交给小刚同学,让其贴上标签.小刚同学区分二者的依据是( )
①我国人口基数大
②我国人口素质偏低
③我国男女性别比失衡
④我国人口老龄化速度加快