The Libians will never forget Oct. 20, 2011, ____ Gaddifi was killed in Sirte,  ____ shocked the whole world..

A．that; which

B．when; which

C．which; when

D．that; that

新池初始投入原料的浓度，一般控制在干物质含量（）为宜。

A.4%-6%

B.8%

C.9%

D.11%