b) He looked the door to prevent the thief from escaping. ( so that )
=> He looked the door so that he prevent the thief from escaping
(Dịch: Anh ta nhìn ra cửa để ngăn kẻ trộm trốn thoát)
Cấu trúc So That mang nghĩa: để, để cho
S + V + So That + S + V