in once spare time中的once 指什么

in once spare time中的once 指什么 in spare time还是on spare time in sb’ spare time造句 on my spare time还是in my spare time in the spare time /on the spare time哪个对? in his spare time or at his spare time 请问:In my spare time是什麽意思? in spare time 前加什么 in one's spare time同义句 in one'spare time的同意词组 take part in,spare time的意思 in my spare time和on my spare time 有什么区别spare time是不是只能和in 连用 spare time Spare time Time can you back once in?once once in a life time I have no time to spare .这句话中的spare是动词还是形容词 spare的用法?in spare time people often like watching tv的意思~