从C、H、O、N、Na、Ca等6种元素中选择恰当的元素，用离子符号、化学式按下列要求填空：

（1）铵根离子______；

（2）可改良酸性土壤的碱是______．

用所给单词的正确形式填空，每空一词。

1. My grandfather wants to live in a _____ (peace) countryside.

2. Male _____ (wolf) will protect their families if there is danger.

3. The little pet's _____ (die) makes me very sad.    

4. We should take the _____ (follow) actions to help the wild animals.

5. _____ (sad), we lost the match in the end