Riddle: What has a bottom at the top, but never takes a seat?

Riddle

what-has-keys-that-open-no-doors-a-space-that-holds-no

Riddle

i-can-be-cracked-made-told-and-played-what-am-i

Riddle

i-have-keys-but-open-no-locks-i-have-space-but-no-room-a60949

Riddle

i-can-slow-you-down-or-speed-you-up-but-im-not-time

Riddle

i-speak-without-a-mouth-and-hear-without-ears-i-have-no-8fa0ce