一个装满水的玻璃杯的总质量为700g，将一金属块放入水中，待水溢出稳定后，把杯的外部擦干，称得其总质量为1040g，将金属块取出后其剩余的总质量为500g，该金属块的质量为 ____g，为该金属块的密度为 ____kg/m³．（忽略金属块带走的水）

将人类的红细胞置于不同浓度的蔗糖溶液中，浸泡半小时之后的结果如图，依照细胞外形的变化判断蔗糖溶液的浓度，由高到低排列，正确的是（  ）

      Hello! My name is Mike. I am from the USA. Now I am in China with my parents. I like China. I like Chinese food, too. I have breakfast at home. I eat an egg, bread and porridge(粥)for breakfast. I do not like milk. I have no time to go home for lunch. So I have it at school. The lunch in our school is good. I can have different food for lunch. I eat rice, meat and vegetables. Sometimes I have noodles（面条） and dumplings(饺子). I have dinner at home with my parents. Sometimes we go out to eat with friends. We have chicken, vegetables and fruit.