What are pebbles called that have been shaped and polished by the wind?

Larry goes to the doctor complaining that he can't see the right side of the visual field with either eye. where in the visual signal-processing pathway is larry's problem occurring?

Which statement best describes a keystone species? o a. it has littlelmenetic variation. it has an extremely high population. 0 b. 0 c. it remains unaffected by all environmental changes. od. it has a strong influence on the ecosystem. 0 e. it's the first species to populate a new ecosystem.

Could someone me with number one you