People think that traffic congestion in the downtown area is due to the increasing number of private cars.

A. Without your assistance, we could get achievement

B. Your assistance discouraged us from get achievement.

C. But for your assistance, we could not have got achievement.

D. If you assisted us, we could not get achievement.

A. If my father hadn't been courageous, I wouldn't have become a chef.

B. It was my father who encouraged me to become a chef.

C. If my father had encouraged me, I would never have become a chef.

D. My father didn't encourage me to become a chef.

A. A rare disease is rumoured to be causing suffering to the leader.

B. It was rumoured that the leader has been suffering from a rare disease.

C. The leader is rumoured to have been suffering from a rare disease.

D. The leader has been rumoured to suffer from a rare disease.

A. Every year, to lay their eggs, migrating birds return to their place of birth.

B. Every year, migrating birds return to their place of birth while laying their eggs.

C. Every year, on returning to their place of birth, migrating birds lay their eggs.

D. Every year, on the journey back to their place of birth, migrating birds lay eggs.