题目

After many years of hard work，the man has finally reached the stage________he has gained good fortune and social status. A．where                            B．that C．which                            D．why 答案：A 解析： 当先行词为stage，position等词时，定语从句常用where或in which引导。 若成等差数列，则的值等于 A.            B. 或          C.                D.