The Vast Majority of Adult Smokers Started Before Age 21

question 16

True/False

The vast majority of adult smokers started before age 21.

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Definitions:

Stomata

Tiny openings or pores often found on the underside of leaves that are involved in gas exchange and transpiration in plants.

Cuticle

A protective and waxy or hard layer covering the epidermis of plants, invertebrates, or other organisms.

Mesophyll

The inner tissue of a leaf, containing many chloroplasts where photosynthesis occurs.

Photosynthesis

The process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water, generating oxygen as a byproduct.