1.please have pity on those who are in danger.请问这句是什么语法,能这样表

1.please have pity on those who are in danger.请问这句是什么语法,能这样表达吗:
please have pity on those person in danger.
2.my grandfather wants to live in a place which is peaceful than here.译这个句子,另这不是比较级的句子吗,peaceful为什么不用more peaceful?还有这which is peaceful 放在句中是什么语法?
3.the old man is sure of living up to one huvdred years old.请问 living此处怎么译?
4.do you want to go swimming this afternoon?yes,if the weather () warm .A will be B would be C was D is
5..i first met her five years ago.请问这句中的first是什么词性,如果是副词那能这样表达吗:met her first.期待你的解答