执行SET INDEX TO <索引文件名表>命令可以打开单索引文件(.IDX)或______文件。
参考答案:复合索引(CDX)文件
(2013·北京,35)—You needn't take an umbrella.It isn't going to rain.
—Well, I don't know.It________do.
A.might
B.need
C.would
D.should
风险评估是什么?