A:2—溴丙烷
B:氯乙烯
C:丙炔
D:甲苯
—Excuse me. Is it my turn now? —Not yet. Please wait on the chair ______your name is called.
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关于x的一元二次方程x2-5x+P2-2P+5=0的一个根为1,则实数P的值是