⑴一份固体溶于水得无色透明溶液,加入足量BaCl2溶液,得沉淀6.63g,在沉淀中加入过量稀盐酸,仍有4.66g沉淀.
⑵另一份固体与过量NaOH固体混合后充分加热,产生使湿润的红色石蕊试纸变蓝色的气体0.672L(保准状况).
下列说法正确的是( )
A:该固体中一定含有NH4+、CO32﹣、SO42﹣、Na+
B:该固体中一定没有Cu2+、Cl﹣、Na+
C:该固体中只含有NH4+、CO32﹣、SO42﹣、Cl﹣
D:根据以上实验,无法确定该固体中有Na+
如图是某家族的遗传图谱,已知控制肤色正常的基因(B)为显性,控制白化病的基因(b)为隐性.请据图回答:
Now more and more people in the world are getting fatter. This troubles them a lot. (1)Experts(专家) say that it has a lot to do with our eating habits. Our eating habits are very important for good health and a strong body. Most of us like eating sweets and ice cream better than vegetables and rice. Sweets and ice cream are not bad for us if we eat them at the end of a meal. (2)If we eat them before a meal, they may take away our appetite(食欲). It's important for us to eat our meal in the same period each day. When we feel worried or excited, we may not want to eat. A long time ago, in England, some judges(法官) often decided whether a man was telling the truth by giving him some dry bread. If the man could not swallow(吞) the bread, it meant that he wasn't telling the truth. Because when a man is worried about something, he will have trouble in swallowing anything dry, because he loses his appetite.