i am sorry i did not follow you.could you please____it again

选用say

区别:
tell(告诉,吩咐,关照) 是vt.,
惯用法:
tell + sb. + about + sth.
tell + sb. + sth.
tell + a story/lie
tell + sb. + that从句

say(讲,说道) 是vt.
惯用法:
say sth. (+ to sb.)
say + that从句

talk(谈,交谈) 是vi.
惯用法:
talk + with + sb.
talk + to + sb.
talk + about + sth

speak(演讲,发言,讲,操...语言) 是vi.&vt.
惯用法:
speak + to + sb.
speak English/Chinese, etc.

say

tell,talk为及物动词, 后面应加说话对象. 而speak后一般接某种语言. 故选say

say
对不起,我没清楚你的意思,可以再说一遍吗?

Say。表示说话内容。

say