$18$. A. It is happiness that
$20$. C. waiting
$9$. C. The
$21$. A. It was my uncle who taught
$8$. B. at
$10$. B. Hobby
$7$. C. in
$12$. B. accompany
$23$. A. Mary
$25$. D. (It + is / was + Adverbial phrase + that + S + V …)
$22$. A. (Buy something + prep + địa điểm)
$17$. B. is to practice