脱氢尾气引入苯加氢装置时，需要（）
A.开启氢压机
B.提高脱氢反应温度
C.脱氢提加料量
D.降低加氢系统压力
参考答案：A
Mr Black decided to give up his farm and devote all his time to______ those children living on the streets.
A．help
B．helping
C．be helping
D．being helped
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