Julia was the only friend ____I made at that time.我知道是定语从句,可是答案只有that,为什么whom不可以呢?

因为有only修饰，所以只能用that

一）只能用that的几种情况 1．当先行词是anything,everything,nothing (something 除外),few,all,none,little,some 等代词时,或者是由every,any,all,some,no,little,few,much 等修饰时 (1) Have you taken down ever...