阅读下面这首唐诗，回答问题。

过山农家

顾况

板桥人渡泉声，茅檐日午鸡鸣。

莫嗔焙茶烟暗，却喜晒谷天晴。

问题：三四句刻画了一位怎样的山农形象？请结合具体词句简要分析。

    Hi. My name is Betty. I'm from Canada. I'm a student. I'm in Class Two, Grade Five. There are four people in my family. They are my father, my mother, my brother and me. My father is an English teacher. He works at a school. My mother is a doctor. She works in a hospital. My brother is a student, too. He is in Class Two, Grade Three. I love my family.

据《自然》杂志报道，科学家最近研究出一种以锶（Sr）做钟摆的钟，它是世界上最精确的钟，锶的原子结构示意图如所示，请回答：

（1）锶原子的核电荷数为　____ 　．

（2）锶原子核外电子层数为____ ．

（3）锶原子最外层容易____ 电子（填“得”或“失”），得到的离子符号为____ ．