21. Have you worked out the problem ______? What a surprise!
A. already B. yet C. soon D. ever
22. I made nay students keep English diaries daily and this brought about the ______ effect.
A. thought B. liked C. desired D. got
23. I've already forgotten ______ you put the dictionary.
A. that it was there B. where was it that C. that where it was D. where it was that
