The scuppers should be plugged____ .A.only if fixed containment is not usedB.only if portable containment is not usedC.only if fixed containment drains are openD.whenever the vessel is being bunkered
The scuppers should be plugged____ .
A.only if fixed containment is not used
B.only if portable containment is not used
C.only if fixed containment drains are open
D.whenever the vessel is being bunkered
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单片机PA2控制共阳极LED时，初始化方法是什么（）A．PORTA|=(1＜＜PA2);DDRA|=(1＜＜PA2);B．DDRA|=(1＜＜PA2);PORTA|=(1＜＜PA2);C．PORTA=~(1＜＜PA2);DDRA|=(1＜＜PA2);D．PORTA|=(1＜＜PA2);DDRA=~(1＜＜PA2);
把PA0管脚方向设置为输入，内部电阻上拉使能的具体方法为（）A．PORTA|=(1＜＜PA0);DDRA=~(1＜＜PA0);B．PORTA=~(1＜＜PA0);DDRA=~(1＜＜PA0);C．PORTA|=(1＜＜PA0);DDRA|=~(1＜＜PA0);D．PORTA|=(1＜＜PA0);DDRA|=(1＜＜PA0);
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