What about the red ones?

[v0031]

When Charles Lee handed me the small red notebook in 1974, he changed my life. “While travelling, you should keep notes on the things you see and do.__16__, you will forget them some day,” he explained. I was staying in his house when travelling in England. 
I took his __17__.I wrote in the notebook every day during the homestay and back to university. I recorded weekend trips, my professors and ideas about my life and future.
When I wrote, I wondered about my __18__ and purpose. Who would read this? Was I recording events and ideas just as a reminder to memory, or was there some larger purpose for this __19__ exercise?
I got a big picture for the task. I was recording events, thoughts, words that were__20__ to my life. I __21__ a future me sitting down to read the pages. I wondered what it would feel like to read those words later.
I filled the notebook Charles gave me. I bought a new one and __22__ it. Then another and another.
Recently, I decided to look through my notebooks in the past 42 years. Charles had been __23__. I remembered the big __24__, the central happenings, but on each page were details I had __25__.
I hadn’t written every day, but I always picked up the __26__ when it felt important. I often wrote in them at school__27__ my students were writing. I wanted to pass on the __28__ Charles had given me. These writings formed a continuous __29__ between my past, present, and future through events in my life.
It took several long evenings to read through my notebooks. As I read, I suddenly realized they are a gift to the __30__me-----I am now the person I was writing to throughout those years.
(   )16.    A. So                B. Instead       C. Moreover       D. Otherwise
(   )17.   A. donation         B.reward           C. advice           D. promise
(   )18.    A. listeners         B.readers          C. students       D. professors
(   )19.   A. daily            B. weekly        C. monthly       D. yearly
(   )20.   A. common         B. important      C. practical       D. similar
(   )21.   A.imagined         B. remembered    C. enjoyed       D. expected
(   )22.    A. wrote             B. filled          C. gathered       D. increased
(   )23.    A.patient            B. serious         C. right          D. wrong
(   )24.   A. mistakes           B. problems      C. accidents       D.events
(   )25.   A.forgotten           B. avoided       C. kept           D. improved
(   )26.   A.drawing         B. travelling       C. reading       D.writing
(   )27.    A. when            B.until         C. before         D. after
(   )28.    A.notebook         B. house          C. lesson          D. effort
(   )29.    A. production       B.connection      C. instruction       D.situation
(   )30.    A.late              B. past          C. present       D. future

[Cokeland Saxton]

20. C
25. A
28. A
30. D

[Smid]

20. C
25. A
28. A
30. D

I disagree with you on a few of these.

I think 20 is "B. Important" - the writer is recording things that s/he considers important about their daily life, things that they wish to remember at some time in the future, when they look back on their life.

I agree that 25 is "A. Forgotten" - the writer remembers the big and important events, but has forgotten the smaller details.

I think that 28 is "C. Lesson" - I believe the writer does not think that the notebook is going to be all that relevant to others, the story isn't about the first notebook that Charles gave the writer in 1974, it's about all the notebooks that have been filled since. The first notebook has prompted an ongoing behaviour. As such, I believe that the writer wishes to pass on the lesson about the importance of keeping these notebooks, not merely passing on the first notebook itself as some sort of first installment of a memoir.

I think that 30 is "C. Present" - although your response of "D. Future" could also be correct. I think "present" is better, though, because the writer says "I am now the person I was writing to throughout those years."