giúp em vs ạ chuyển đôi các câu sau thành câu có mệnh đề quan hệ 1,i remember the day.I was afraid to use my new computer then ....... 2,I work in an office.In my office,the software changes frequently ...... 3,The secretary can give you the information.She sists at the frist desk on the right .... 4, the playground wasn't used by those children.It was built for those children ...... 5,People often suffer from backache.Their work involves standing for most of the day .....