问题：
Gary Locke , a Chinese-American, once______ as the governor of Washington for 8 years and now is U．S．Commerce Secretary．
A.had worked
B.worked
C.is working
D.has been working
Gary Locke , a Chinese-American, once______ as the governor of Washington for 8 years and now is U．S．Commerce Secretary．
A.had worked
B.worked
C.is working
D.has been working
A.had worked
B.worked
C.is working
D.has been working
参考答案：