单项选择题
Questions 20 to 22 are based on the conversation you have just heard.
A．Produce the appropriate sound. B．Press the right-hand lever first. C．Raise their heads above the water. D．Swim straight into the same tank.
A．Students who scored low standardized tests. B．Black freshmen with high standardized test scores. C．Students who are accustomed to living in dorms. D．Black students from families with low incomes.
A．The jury’s prejudice against his race. B．The evidence found at the crime scene. C．The two victims’ identification. D．The testimony of his two friends.