Riddles- here are some riddles...more to come

It goes up, but at the same time goes down. Up toward the sky, and down toward the ground. Its present tense and past tense too, come for a ride, just me and you. What is it?

Highlight--->See-saw<----for answer

Old Mother Twitchett had but one eye, and a long tail which she let fly; and every time she went through a gap, a bit of her tail she left in a trap. What is she?

Highlight--->Needle and thread<----for answer

Never resting, never still. Moving silently from hill to hill. It does not walk, run or trot, All is cool where it is not. What is it?

Highlight--->Sunshine<----for answer

What goes around the world and stays in a corner?

Highlight--->A post stamp<----for answer

Take one out and scratch my head, I am now black but once was red. What am I?

Highlight--->A match<----for answer

Some will use me, while others will not, some have remembered, while others have forgot. For profit or gain, I'm used expertly; I can't be picked off the ground or tossed into the sea. Only gained from patience and time, can you unravel my rhyme?

Highlight--->I’m knowledge<----for answer