What does 달아 in "답글 달아 주요" mean?

I know "답글 달아 주세요"means "please replay a message", but what does 달아  mean?

I hope someone teach me the meaning, thank you!

※ 주요 ------> 주세요

A story with hidden meaning I would like to introduce a story that is a usual story at a glance but has actually scared meaning. Please think true story. "Today my earphones worth $98 have broken. I can't hear suddenly any sound from my earphones although it was expensive... I was getting to be angry then slammed down plasma display panel TV worth $450. When suddenly I found myself checking if TV were broken or not. I was relieved but no sounds. $450 TV was broken too. By the way It's been quiet today. I'll go to walking to refresh myself." ※reference: https://matome.naver.jp/odai/2138249505395682301

A story with hidden meaning

I would like to introduce a story that is a usual story at a glance but has actually scared meaning. Please think true story.

"Today my earphones worth $98 have broken. I can't hear suddenly any sound from my earphones although it was expensive... I was getting to be angry then slammed down plasma display panel TV worth $450. When suddenly I found myself checking if TV were broken or not. I was relieved but no sounds. $450 TV was broken too. By the way It's been quiet today. I'll go to walking to refresh myself."

※reference: https://matome.naver.jp/odai/2138249505395682301

What is life for you?

I would like to know your own answer of "What is life for you? This is the question I asked several years ago when I was a university student taking English class. I compared it to piano(because of my hobby) and said "Life is like a piano. white key is happiness and hope. Black key is sorrow and despair. A piano makes a beautiful sound because it has both of that"

中文自我介绍 我叫 远藤肾太郎。 我 今年 二十五岁。我家 在 名古屋。 我家 有四口人。我有一个哥哥。 两年前 我大学毕业了。 现在 我在汽车制造商 工作。 每天 早上 九点 上班， 八点 下班。工作 很忙。 下班 以后， 我去 便利店 买 便当， 有时候 和 朋友 一起 看 电影。 周末 我在家 弹钢琴， 或者 打台球。 我喜欢中国菜。请大家 多关照。