减压阀在液压系统中起调压作用，正常工作的出口压力保持恒定，不工作时阀内回路处于常闭状态（）
参考答案：错
金融深化需要财政政策的配合，包括合理规划财政税收，例如减少不必要的财政补贴、配给及增税而增加社会总收入。( )
His father _______ in Beijing last Wednesday. But he _______ in Shenyang now. [ ]
A. is; was
B. was; is
C. were; is
D. were; was
