Everyone will go through life's stages of ups and downs, _____ self-respect plays a key role in the maturity

of a person. [ ]

A. when

B. which

C. as

D. that

在Access表中，可以定义3种主关键字，它们是

A．单字段、双字段和多字段

B．单字段、双字段和自动编号

C．单字段、多字段和自动编号

D．双字段、多字段和自动编号