根据句意填写单词或依据首字母填空

根据句意填写单词或依据首字母填空
1.Friendship is a___
2.Not everyone has __care in the country.They can't be treated well in hospital.
3.Scientists have carried out extensive r____ into renewable energy sources.
4.---Don't eat too much hot food or you will get p___.
---Human beings will die out.
5.Teacher's smile makes student feel c___ about answering questions
能答上来几个算几个.最好都能,呵呵