5. My friend George, that arrived late, was not permitted to enter the class.

=> who (sau dấu "," không dùng "that")
6 . On the way home, we saw a lot of men, women and dogs which were playing in the park.

=> that (phần cụm danh từ gồm cả người lẫn vật => ko dùng which)
7 . Chemistry is one branch of science on that most of the industries depend.

=> which (sau giới từ không dùng "that")