35. The langur population and its habitat is monitored by the Cat Ba Langur Conservation Project.
=> It is by the Cat Ba Langur Conservation Project that the langur population and its habitat is monitored.
36. These animals are most active during the hours of twilight around dawn and dusk.
=> It is during the hours of twilight around dawn and dusk that these animals are most active.
37. Jean picked up a wallet on the way home yesterday.
=> It was a wallet that Jean picked up on the way home yesterday.
38. In my opinion, you should not eat lukewarm food so often.
=> I don't think you should eat lukewarm food so often.
39. Keywords: was/the/she/It/she/complained./because/was/unhappy/
=> It was because she was unhappy with the price that she complained.
40. It/be/in/cave/they/have/ trap / 19 hours / before / rescue.
=> They have been trapped in a cave for 19 hours before rescue.