Answer:
Sometimes I fly as fast as the speed of light. Sometime I crawl as slow as a snail. Unknown until I am measured but you will certainly miss me when Iβm gone.
I shift around though always slowly. I never move more than a few inches at a time. A large movement by me can kill many people. I am huge yet unseen by humans.
I am an English word with three consecutive double letters. What am I?
You throw me out when you want to use me, but take me in when you donβt want to use me. What am I?
People need me, yet they give me away every day. What am I?
I am your mother's brother's only brother in law. Who am I?