Answers:

     `1.` B.        `2.` A.       `3.` D.          `4.` C.       `5.` C.

Detail:

Exercise 105:

    Question `1`: I haven't heard from Maria for many months.

    Question `2`: This book is so long that I haven't finished it yet.

    Question `3`: Spain was being at one time a very powerful country.

    Question `4`: The longest fish in the contest was caught by Thelma Rivers.

   Question `5`: "Are we about to have dinner?" - "Yes, it is being served in the dining room."

Question 1. I haven't heard from Maria _____.
A. since many months before
B. for many months
C. for many months ago
D. since a long time
Question 2. This book is so long that I _____.
A. haven't finished it yet
B. haven't finished it already
C. still have finished it
D. still haven't finished it already
Question 3. Spain _____ at one time a very powerful country.
A. was
B. has been
C. is

D. was being

Question 4. The longest fish in the contest _____ by Thelma Rivers.
A. was catching
B. caught
C. was caught
D. catch
Question 5. "Are we about to have dinner?" - "Yes, it _____ in the dining room."
A. is serve
B. have been served
C. is being served
D. served