Questions 1-4 refer to the following e-mail from a student to a teacher.

Mr. Williams:

I (1)..... sooner, but I have been so busy here in Africa. I know that you instead I (2).... as soon as I got here, but this is the first time that I've had some free moments. Please forgive me. By the way, you (3).... that just ignored your advice to bring extra water bottles. But I knew that our program was going to give us some for free! Anyway, it is essential that we (4).... in touch as I'll be gone for an entire year.

Thanks!

Katie O'Neill