[Solved] Current events: A) often are used to discuss important issues in global education. B) focus on the views of our citizens and so really do not internationalize the curriculum. C) are used by few teachers. D) are difficult to access information for use in elementary and middle schools. Microorganisms: Very small, often single-celled organisms that can be bacteria, fungi, viruses, or protozoa, not visible to the naked eye. Iron Formation: A sedimentary rock consisting of alternating layers of iron-rich minerals and silica or carbonate, typically formed in Precambrian seas. Seawater: The saltwater that makes up the oceans and seas, covering more than 70% of the Earth's surface, containing various salts and life forms. Silica-rich Organisms: Organisms that produce silica (silicon dioxide) as part of their structure, such as diatoms and certain sponges.