Which key sentence from the passage identifies this
text as a primary source?

Complete the activity titled "comparative urban environments." every city is shaped by different cultural forces. in one to two paragraphs, contrast the culture of two different cities from this activity: new york and buenos aires. what makes these cities stand apart from each other culturally? what is unique about each city’s attitude, language, habits, foods, or architecture?

Which of the following types of nonrenewable fuel sources requires the storage of radioactive waste? a. coal b. nuclear c. solar d. oil

Which of the following can scientists estimate geologic time? a. observing rock sequences b. radiometric dating c. comparing fossils d. all of these