Nowadays more people are advised to arrange for insurance_____they need medical care.

A．in order

B．in need

C．in case

D．in hope

为提高PC机主存储器的存取速度，出现了多种类型的DRAM内存条，若按存取速度从低到高排列，正确的顺序是( )。

A．EDO DRAM，SDRAM，RDRAM

B．EDO DRAM，BDRAM，SDRAM

C．SDRAM，EDO DRAM，RDRAM

D．RDRAM，EDO DRAM，SDRAM