Answer:
Gets rid of bad ones, short and tall. Tightens when used, one size fits all.
It is able to speak because it has a hard gone. You know what it is as soon as it has sung. What is it?
What is given but kept by the giver?
Being able to interpret the letters on this screen proves that you have this quality.
I'm a bacteria that causes typhoid What's my name ?
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.