________ volleyball is her main focus, she's also great at basketball.
A. Since
B. Once
C. Unless
D. While
________ volleyball is her main focus, she's also great at basketball.
A. Since
B. Once
C. Unless
D. While
D解析：since“自……以来”；once“一旦”；unless“除非”；while“虽然，尽管”。句意：“虽然排球是她的专项，她篮球打得也不错。”故选D项。