Test on Present Perfect: “Conversational Past Tense”

• Rockefeller became an assistant bookkeeper at age 16 and went into several business partnerships beginning at age 20, concentrating his business on oil refining. His wealth soared as kerosene and gasoline grew in importance, and he has become the richest person in the country, controlling 90% of all oil in the United States at his peak. Rockefeller became the country's first billionaire, with a fortune worth nearly 2% of the national economy.
• Rockefeller became an assistant bookkeeper at age 16 and went into several business partnerships beginning at age 20, concentrating his business on oil refining. His wealth soared as kerosene and gasoline grew in importance, and he became the richest person in the country, controlling 90% of all oil in the United States at his peak. Rockefeller became the country's first billionaire, with a fortune worth nearly 2% of the national economy.