Answer:
Both <em>los </em>and <em>las</em> are definite articles for plural nouns in the Spanish language. The difference is that<em> </em><em>los</em> is used for plural masculine nouns (plural form of <em>el</em>), while <em>las</em> is used for plural feminine nouns (plural form of <em>la</em>). As a good example, we can take the names of cities Los Angeles and Las Vegas. Los Angeles is actually the plural form of <em>el angel</em>, meaning<em> the angel</em>, while the singular form of Las Vegas is <em>la vega</em>, meaning <em>the meadow</em>.
Another example:
el perro - the dog los perros - the dogs
la vaca - the cow las vacas - the cows
if you are lawfully arrested by an officer who has probable cause to believe that you have been driving under the influence, then you consent to taking a chemical test of your blood or breath for the purpose of determining your blood alcohol content
