She has been concentrating on her ________.
A. careers
B. career
C. a career
D. some career
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The Prime Minister has, _______________, seen off the challenge of the opposition...
A. the meantime
B. in the meantime
C. at the meantime
D. for the meantime
【单选题】变频器的U、V、W是( )端子。
A. 输入电源
B. 输出电机
C. 故障输出
D. 输出控制信号
【单选题】西门子MM440通用变频器有________组模拟量输入端子。
A. —
B. 两
C. 三
D. 四
【单选题】变频器的模拟量给定、多段速控制等是变频器__________控制方面的功能参数
A. 运行
B. 调速
C. 加、减速
D. 功能
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