艾滋病(AIDS)是一种严重威胁人类健康的传染病.下列有关艾滋病的说法不正确的是( )
A:艾滋病的病原体是人类免疫缺陷病毒(HIV)
B:艾滋病患者的泪液、乳液和尿液中有病原体
C:静脉注射毒品和不安全性行为最容易传播艾滋病
D:我们不能与艾滋病患者接触与交流,以免被传染
向CuO和铁粉的混合物中加入一定量的稀硫酸,微热,充分反应后冷却,过滤,在滤液中放入一枚洁净的铁钉,发现铁钉表面无任何变化,据此判断下列结论正确的是( )
A
Linda,14
My mother does most of the housework like cooking and folding the clothes.My father can only do the washing,sweep the floor and take out the rubbish.He really needs to learn how to do the housework.
Celina,13
My mother and my father do 50% of the housework each.My mother does the washing and cleans the living room.My father makes the bed and drives me to school.
Paul,16
My father doesn't do a lot but he tries to help.He hangs__up the clothes after my mother washes them and my mother is happy that he always gives her a hand.
Bill,15
My mother is a doctor.She is busy with her work every day,so she has little time to do the housework.In fact,she isn't good at doing it.So my father has to do most of it.Sometimes my grandmother comes to help.
如图,在1x2网格的两个格点上摆放黑、白两个棋子,使两棋子不在同一条格线上.其中恰好如图示位置摆放的概率是( )