题目

Once Napoleon stayed in a small inn. The next morning, he went to thank the innkeeper. “You have served me well, innkeeper,” said Napoleon. “I wish to reward you. Tell me what you want.” “Sir, we want nothing,” said the innkeeper. “But will you tell us something?” “What is it?” Napoleon asked. “We have heard a story,” said the innkeeper, “that once during the war, a small village was taken by the Russians. You happened to be in the village. You hid while they looked for you. Will you tell us how you felt when they were looking for you?” Napoleon looked ve下列说法中正确的是（  ）A．力是物体对物体的作用，总是成对出现的B．只有固体之间才能发生相互作用C．重力就是地球对物体的吸引力D．重心就是物体上最重的一点