Simple riddles for teens with simple answers

I have all the knowledge you have. But I am small as your fist that your hands can hold me. Who am I?

I have four legs. I live in Africa. I am big and grey. I live in the river. What am I?

What goes up when rain comes down?

They are twin sisters, same height; they work in the kitchen, arm in arm. Whatever is cooked, they always try it first.

I have a face like a tree and skin like the sea. A great beast I am, yet small vermin frighten me. What am I?

I'm a soft and furry pet. I have four legs and a long tail. I have sharp teeth and claws. I like to chase mice. I am a...

Give me food, and I will live. Give me water, and I will die. What am I?

I live in the ocean. I have eight legs, two big claws and a tail. My body has a hard shell. I eat anything I can find. I am a...

What do you call a cat crossed with a fish?

What time of day, when written in a capital letters, is the same forwards, backwards and upside down?