I.1 hoa worked hard-c so she passed her exam
2 lan is sick today-b so she won't go to school
3 hoai woke up late-a so she didn' have time for breakfast
4 it was hot-d I returned on the air conditioner
II.1 nam went on excursion to oxford last sunday
2 he went there by bus
3 he met some english students in the bookshop
4 he practiced speaking english with many foreigners
5 in the afternoon he bought a dictionary and a book " oxford university"
6 yes he did
III.1 from
2 on
3 to
4 by
IV.1 I wish I had an Iphone
2 she wanted to go home because she was tired
3 the examiner asked lan if she spoke english