“Could you tell me______?”

“ Yes. They ____ to the library.”[ ]

A. where are the twins, have been    

B. where were the twins, have been

C. where the twins are, have gone    

D. where the twins were, have gone

PC机中DRAM内存条的类型有多种，若按存取速度从高到低的顺序排列，正确的是()。

A．SDRAM，RDRAM，EDODRAM

B．RDRAM，SDRAM，EDODRAM

C．EDODRAM，RDRAM，SDRAM

D．RDRAM，EDODRAM，SDRAM