How Long Did It Take for Oxygen to Build Up

question 25

Multiple Choice

How long did it take for oxygen to build up in the Earth's atmosphere to its present levels?

• A) at least 542 million years
• B) at least 360 million years
• C) at least 2 billion years
• D) at least 3.5 billion years

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Definitions:

Operating Income

Operating income is the amount of profit realized from a business's core operations, excluding taxes and interest expenses.

Negative Net Cash Flow

A situation where a company's outgoing cash exceeds the incoming cash during a specific period, indicating potential financial trouble.

Financial Statements

Structured reports that detail the financial performance of an organization, typically including the balance sheet, income statement, and cash flow statement.

Depreciation Expenses

The allocation of the cost of tangible assets over their useful lives, recognized as an expense on the income statement.