What Am I Riddles

Question: There are several different kinds, but the one you pick doesn't do its job.

What is it?

Question: What do you use to hoe a row, slay a foe, and wring with woe?

Question: I have two rings. I move by request. If the mixture isn't right I just sit and rest.

What am I?

Question: I go up and I go down,
towards the sky and the ground.
I'm present and past tense too,
Let's go for a ride, me and you.

What am I?

Question: You can easily touch me, but not see me.
You can throw me out, but not away.

What am I?