According to Geological Evidence and Computer Models Based Upon That

question 6

Multiple Choice

According to geological evidence and computer models based upon that evidence,which statement about the concentration of oxygen in our atmosphere is correct?

• A)No oxygen was present prior to the Cambrian;oxygen levels have uniformly risen since and today's atmosphere is more oxygen rich than at any time in Earth's history.
• B)Oxygen levels were greatest during the Cambrian but have been steadily declining ever since;today's atmosphere is less oxygen rich than at any time in Earth's history since the Precambrian.
• C)Oxygen levels have generally risen during the Phanerozoic but peaked during the Mesozoic ("age of dinosaurs")and declined sharply in the Early Cenozoic.
• D)Oxygen levels have generally risen during the Phanerozoic but peaked during the Late Paleozoic ("age of coal swamp forests")and declined sharply in the Early Mesozoic.

---

Definitions:

Quick Analysis Tool

A feature in software that allows users to quickly access data analysis methods relevant to their data.

Home Tab

The Home Tab is a primary tab in many software applications that provides quick access to the most commonly used commands and tools, such as formatting, clipboard, and paragraph settings.

Conditional Cell Formats

A feature in spreadsheet software that changes the format of a cell based on certain criteria, such as values being above a threshold.

CTRL

A control key on a computer keyboard that, when pressed in conjunction with other keys, executes specific commands.