18, B - after past perfect + past simple
19, B - past simple
20, B - future simple as soon as present simple
21, C - present simple + when + past
22, C - present continuous
23, C - always (từ chỉ hành động diễn ra hằng ngày) → present simple
24, C - at present (từ chỉ hiện tại) → present continuous
25, D
$\text{Chúc bn hok tốt}$
$\text{Xin CTLHN!}$
$\text{#BTS}$
