请用化学用语填空．
（1）镁元素____；
（2）3个汞原子____；
（3）硝酸钡____；
（4）标出锰酸钾中锰元素的化合价____．

图1是我国局部地区图，图2是某地作物种植景观图，读图完成以下问题。

Welcome to the City Zoo! There are many1in the zoo. Let’s see the koalas first. Koalas are2Australia. They are quiet,3and cute. Children like them very much. The kangaroos (袋鼠) are also from4. They are quiet and interesting,5they are not friendly.
The giraffes come from Africa. They have a6neck (脖子). They like to eat leaves. The lions are also from Africa. They are exciting, but a little7. Many people don’t like8. We also have pandas. They are from China. They are very cute and friendly, but they are very shy. So please be9.
Have10and enjoy yourself here!

已知函数$f\left(x\right)=x^2-2x+3$在区间$0,t$上有最大值3，最小值2，则$t$的取值范围是(    )