i'll (take)it.为什么不是buy?get?

i'll (take)it.为什么不是buy?get? 我将买它 用英语翻译是I'll take it ,为什么不是I'll buy it 为什么英语对话里不说I’ll buy it.却说I'll take it. i'll buy it与i'll take it The CD is very cheap ,i 'll take it .为什么此处take 不能换成buy 类似的,F I'll take it . I'll take it I'll take it.是什么意思 I’ll take it 英语 I'll take it thanks The five erasers are on sale.I'll () five.为什么用take,不用buy? He'll buy the watch ____ it may take.