Why Do Influenza Pandemics Occur? (Select All That Apply)

question 86

Multiple Choice

Why do influenza pandemics occur? (Select all that apply)

• A) a hybrid virus is produced by antigenic shift
• B) no hosts have any previous immunity to the new hybrid produced by antigenic drift
• C) worldwide events facilitate the movement of hosts from one continent to another
• D) the human portion of a hybrid virus attacks cytotoxic T cells

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Credit Memo

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Gross Profit

Revenue minus the cost of goods sold (COGS), representing the profit a company makes after deducting the costs associated with making and selling its products.

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A set time period during which a discount is available, or the period between the issuance of a bill and its payment due date where a discount may be taken for early payment.

Credit Memo

A document issued by a seller to a buyer, reducing the amount the buyer owes to the seller under the terms of an existing invoice.