题目

In 1977, Jack, an Italian-American who lived in San Francisco, flew from America to Italy to visit his relatives. On the way, the plane made a one-hour stop to refuel(加油)at the New York Airport. Thinking that he had arrived, Jack got out and spent three days in New York, believing he was in Rome. When his relatives were not there to meet him, Jack thought they had been caught in the heavy Roman traffic mentioned in their letters. While looking for their address, Jack could not help noticing that modernization had changed most, if not all, of the ancient city’s landmarks. He also noticed 已知反应X＋Y＝M＋N为吸热反应，对该反应的下列说法中正确的是（ ）A. X的能量一定低于M的能量B. Y的能量一定低于N的能量C. X和Y的总能量一定低于M和N的总能量D. 因该反应为吸热反应，故该反应一定要加热才可发生