多项选择题
Given: Which two statements are true?（）
A.The output could be 8-1 7-2 8-2 7-1 B.The output could be 7-1 7-2 8-1 6-1 C.The output could be 8-1 7-1 7-2 8-2 D.The output could be 8-1 8-2 7-1 7-2
单项选择题 Given: What is the result?（）
单项选择题 Given that t1 is a reference to a live thread, which is true?（）
