【简答题】The Age of Discovery, also called the Age of Exploration, is a historical period of European global exploration that started in the early 15th century and continued until the 18th century. It is usual...
【单选题】A bottle of wine can be produced in France with 2 labor hours, and in the United States with 4 labor hours. A p ound of beef can be produced in France with 1 labor hour, and in the United S tates with...