18.Yes. A huge earthquake shook our city last month. (Make a question)
=>did a huge earthquake shake your city last month
19. The government have sent lots of equipments and planes to put out the forest fire. (Passive voice)
=>.lots of equipments and planes have been sent  to put out the forest fire by the government
20. I think you should use energy efficient light bulbs. (Using conditional sentence type 2)
=>.  if i were you , i woul use energy efficient light bulbs