During the Quarter of a Century Prior to 2000, Between

question 125

Multiple Choice

During the quarter of a century prior to 2000, between 66 percent and 71 percent of Americans age 18 and older paid personal income taxes. What happened to the share of adult Americans with a personal income tax liability between 2000 and 2009?

• A) It rose to nearly 90 percent.
• B) It rose to approximately 80 percent.
• C) It was virtually constant at approximately 70 percent.
• D) It fell to 51 percent.

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Definitions:

Vas Deferens

The vas deferens is a long, muscular tube that transports mature sperm from the epididymis to the urethra in anticipation of ejaculation in male mammals.

Seminiferous Tubules

Highly coiled tubules within the testes where spermatozoa are produced.

Ejaculation

The process of expelling semen from the penis during sexual climax, facilitated by muscle contractions.

Acrosome

A cap-like structure over the anterior portion of a sperm's head, containing enzymes that help the sperm penetrate the egg.