单项选择题
In what aspect do Betty and Abby differ from most twins（）
A．They make decisions by tossing coins. B．They are not physically separated. C．They think exactly the same way. D．They share most of their vital organs.
单项选择题 What does the man mean（）
单项选择题 What does the woman mean（）
单项选择题 What does the passage tell us about American rivers（）
