The Greatest Progress in Reducing Atmospheric Levels of Lead Pollution

question 21

Multiple Choice

The greatest progress in reducing atmospheric levels of lead pollution resulted from

• A)the elimination of leaded gas.
• B)the switch from lead to graphite in pencils.
• C)the development of new types of batteries that use lithium instead of lead.
• D)new types of lead scrubbers on smokestacks that removed lead from the air.

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Definitions:

Semitendinosus

A muscle in the thigh that is part of the hamstring group, responsible for bending the knee and extending the hip.

Intercostal

Between the ribs.

Pectoralis Major

A large muscle in the upper chest that helps in the movement of the shoulder and the arm.

Beneath

A preposition used to describe something located at a lower level or layer than something else.