综合递减率指老井单位时间内油气产量的变化率或什么？
参考答案：下降率
He took pity on the people in the flooded areas and___ his clothes and quilts to them.
A．gave away
B．gave out
C．broke out
D．sent for
与HBV共存时才具有感染性的是
A．HAVB．EB病毒C．HDVD．HCVE．HEV
