Answer:
It is a sound of empty, speak and it'll talk back plenty. But all the more you yack, you'll get the same words back.
I am the yellow hem of the sea's blue skirt.
A time when they're green. A time when they're brown. But both of these times, cause me to frown. But just in between, for a very short while. They're perfect and yellow. And cause me to smile.
In the land of the green glass door there are riddles but no answers, sheets but no blankets, and books but no words. Name something found in the land of the green glass door.
What goes up when the rain comes down?
People take me on walks and I run and have fun. What am I?