41. The children left the house. Then the house collapsed.

→ The children_______________________________________________ (before)

42. After the latest landslide in Sapa, the local government held a training session to teach people how to protect themselves in some natural disasters.

→ After_______________________________________________________ (was)

43.     We will visit the Emancipation Park before we go to have some drinks in that famous bar.

     → .............................................................................................. (as soon as)

44.     They invited me to travel to Los Angeles with them after I had planned my trip to England.

     → ..................................................................................................................

          .............................................................................................. (by the time)

45.     The local government displayed many educational posters on the street to encourage people to protect the environment.

     → ..................................................................................................................

          ....................................................................................................... (were)