The fact that children in different cultures in the age at which basic motor skills appear demonstrates that a. vary somewhat; genetic factors can slow or accelerate early motor development b. vary somewhat; environmental factors can slow or accelerate early motor development c. do not vary; genetic factors alone determine early motor development d. do not vary; environmental factors alone determine early motor development

A.vary somewhat; genetic factors can slow or accelerate early motor development.

Wetlands form where water and land meet. a lake with a wetland fringe can fill in with decayed plant and animal material to become a wet meadow. a pond can fill in to become a bog or fen. sediment can fill in a river marsh to become a swamp.flooding of coastal lowlands from rising sea levels has created broad coastal marshes that are protected from wave action by barrier islands or reefs. coastal wetlands also form when rivers deposit sediment as they reach the ocean. plants then take root and hold the soil firm against the forces of tides and waves.