I like onions.      healthy.

阅读判断。   Today we go to the zoo. There are so many animals in the zoo.Look! There are black and white. They are fat. They eat bamboo. Look at the elephant. It's so big. Its nose is so long, and the ears are big. Look at the monkey. It's thin. It lives in the tree. It eats bananas. I love animals. They are so lovely.

t℃时，在饱和硫酸铜溶液中加入a g无水硫酸铜，恢复至原温度可析出b g硫酸铜晶体。说法正确的是（   ）

离子反应、复分解反应、置换反应和氧化还原反应之间可用集合关系表示，其正确的是（   ）

古希腊哲学家赫拉克利特说：“上坡路和下坡路是同一条路。”这其中蕴涵的哲理是