I don't have white shoes for tomorrow's speech contest.----My brother has_____ pair.whould you like to try ____on?A a it B one it C one them D two them我是想问在这里不用one是因为one强调的是个数 所以不用,另外请说明一下a和one的区别 ,即：在什么情况下选a什么情况下选one She got up to get some sleeping pills but found there was ____left at home.A nothing B none C　something　D nobody在这里求说明一下none和nody的区别 为什么选none

I don't have white shoes for tomorrow's speech contest.
----My brother has_____ pair.whould you like to try ____on?
A a it B one it C one them D two them
我是想问在这里不用one是因为one强调的是个数 所以不用,
另外请说明一下a和one的区别 ,即：在什么情况下选a什么情况下选one
She got up to get some sleeping pills but found there was ____left at home.
A nothing B none C　something　D nobody
在这里求说明一下none和nody的区别 为什么选none