某类房地产2005年-2009年的价格见下表，各年增长量的权重分别为0.1、0.2、0.2、0.5，则利用平均增减量法预测该类房地产2010年得价格为（）元/平方米。

A.8460　　

B.8500　　

C.8790　　

D.8838

It is believed that a new kind of drug ______ by the scientists and they are hopeful that they will succeed in a few months.

A．has been developed

B．is being developed

C．is developing

D．has developed