— Lily and Lucy look the same. 

— That's true. Sometimes it is really difficult to _____ them apart.  [ ]

A. tell

B. say

C. talk

D. speak

— Sorry, I forget to post the letter for you.

— Never mind, _____ it myself tonight.

A．I’m going to post

B．I’ve decided to post

C．I’ll post

D．I’d rather post