或是⋯⋯，或是⋯⋯
Explanation
“或是⋯⋯，或是⋯⋯”用于列举两种可能的情况或选择，表示非此即彼的关系，强调二者必居其一。
This structure presents two mutually exclusive possibilities or choices, emphasizing that one of the two options must be true or selected.
Examples
这件事或是哥哥做的，或是弟弟做的。
This matter was either done by the older brother or by the younger brother.
你或是参加这次考试，或是明年再学一遍这门课。
You either take this exam or retake the course next year.