useless trivia: What Word Means: To Surmise?

Questions

The mullet fish only turns _____ after death?

The Goliath frog of West Africa is nearly _____ feet long?

To make half a kilo of honey, bees must collect nectar from over ___ _______ individual flowers?

Vampire Bats can hear sound frequencies which are over _____ times higher than any picked up by the human ear?

The male Californian sea-otter grips the nose of the female with his teeth during?