Luyện ngữ pháp - English Grammar in Use - Intermediate
Unit 67: See somebody do and see somebody doing

STT	Tên task	Số câu hỏi
1	Grammar Explanations and Rules	1
2	Exercises - 67.1	7
3	Exercises - 67.2	6
4	Exercises - 67.3	12

Unit 66: To ... (afraid to do) and preposition + -ing (afraid of -ing)

Unit 68: -ing clauses