By ________, Most Children Know the Numbers to 20

question 143

Multiple Choice

By ________, most children know the numbers to 20.

• A) age 2
• B) age 3
• C) age 4
• D) age 5

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Definitions:

Coefficient of Variation

A standardized measure of dispersion of a probability distribution or frequency distribution, expressed as a percentage of the mean.

Ether

A class of organic compounds characterized by an oxygen atom connected to two alkyl or aryl groups; they are often used as solvents.

Molecule

The smallest particle of a chemical element or compound that has the chemical properties of that element or compound.

1,2-dibromoethene

A halogenated alkene with the formula C2H2Br2, characterized by having two bromine atoms attached to adjacent carbon atoms in the ethene molecule.