25, A – Observation (n- sự quan sát)
26, B – for (compulsory for sb (to do sth): bắt buộc cho ai (làm việc gì))
27, C – take (take an exam: làm một bài kiểm tra)
28, D – follow (follow a class: theo học 1 lớp học)
29, E – requirements (n- yêu cầu)
31, C – aren’t I
32, B – not to come
33, B – had
34, B – had already begun
35, C – although
36, A – By the time you return
37, C – of
38, A – to leave
39, B – donation
40, C – the
41, D – are they
42, B -put
43, A – wouldn’t suffer
44, A - arrived
