【简答题】In some western countries, it is believed that a person is in great er of illness when he sneezes (打喷嚏). Therefore, people will express wishes when they hear others sneeze. The person who sneezed ...
【单选题】By the 1820's in the United States, when steamboats were common on western waters, these boats were mostly powered by engines built in the West (Pittsburgh, Cincinnati, or Louisville), and of a distin...