We forgot ... the letter. Sorry, you asked to do it.
a) posting
b) to post
c) post
d) having post
e) posted

I'm looking out of the window, but i am not ... him
a) not see
b) haven't seen
c) don't see
d) am not seeing
e) doesn't see

1) b) to post 2) c) don't see

We forgot to post the letter. Sorry, you asked to do it. (b)I'm looking out of the window, but I don't see him. (c)