单项选择题
According to one theory, when the glaciers disappeared, birds（）
A．stopped migrating B．continued migrating C．began migrating again D．migrated south and stay there
单项选择题 This passage supports the belief that（）
单项选择题 The underlined part "the law is loaded against him" in the second paragraph is most likely to mean （）
单项选择题 Which of these statements is true（）
