=>

10. Having refused  Linh's offer of a lift in his car, Huong had to walk home.

11.  Thanh admitted having forgotten to turn off the gas cooker before leaving the house.

12. Having planned the content, we're now looking for supporting information.

13. Mai regretted not having learned hard.

14. Having treated the environment irresponsibly, humans now have to suffer.

15. Hieu admitted having broken this vase.

#No_copy

10 . Since Huong had refused Linh's offer of a lift in his car, hshe had to walk home.

=> Having refused  Linh's offer of a lift in his car, Huong had to walk home.

11  . Thanh had forgotten to turn off the gas cooker before he left his house. He admitted that.

=>Thanh admitted having forgotten to turn off the gas cooker before leaving the house.

12 . After we have planned the content we're now looking for supporting information

=> Having planned the content, we're now looking for supporting information.

13 . Mai had not learned hard. She regretted it

=>Having treated the environment irresponsibly, humans now have to suffer.

14 . Since humans have treated the environment irresponsibly, they now have to suffer.

=> Having treated the environment irresponsibly, humans now have to suffer.

15 .Hieu had broken this vase.He admitted that. 

=> Hieu admitted having broken this vase.