一艘远洋船舶需要有大约（）①4000件备件；②价值60万美元的备件；③价值30万美元的备件。
A.①对
B.②对
C.①+②
D.①+③
参考答案：C
下列所示的实验操作与方法正确的是 ( )
The nurse provides care for a client with chronic obstructive pulmonary disease (COPD). Administering high doses of oxygen may produce what result ？（）
A．Increased respiratory drive.
B．Diminished respiratory drive.
C．A mismatch between ventilation and perfusion.
D．A profound decrease in partial pressure of arterial carbon dioxide (PaCO2).
