In Prescientific Times, a Discredited Notion Held That Human Health

question 135

Multiple Choice

In prescientific times, a discredited notion held that human health depended on the correct balance of four "humors," including blood, which was not known to circulate.At that time, leeches were used in bleeding to supposedly reduce the amount of blood as a humor, but today

• A) leeches are used to eliminate pools of coagulated blood.
• B) ticks are used to encourage bleeding.
• C) earthworms are used to reduce blood throughout the body.
• D) there is no use of leeches in medicine.
• E) leeches are important in soil development.

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Definitions:

Condensed Structural Formula

A condensed structural formula is a method of describing the elements or molecules that compose a compound and their arrangement in a compact form without drawing full structural diagrams.

Dimethylbutane

An organic compound with the formula C6H14, a type of alkane that is used as a fuel.

Dimethylpentane

An isomer of hexane, used as a reference fuel in octane rating and found in various petroleum distillates.

Ethylbutane

A chemical compound that is a structural isomer of octane, with the formula C6H14.