A) influencing B) to be influenced

C) having influenced D) being influenced

54. Richard has insured his life for a large amount _____ his wife and two sons.

A) for the sake of C) in case of B) in the event of D) in the case of

55. The Canadian called Da Shan can speak Chinese fluently as if he _____ a Chinese.

A) is C) was B) were D) had been

56. Now children are _____ to smallpox（天花）as a result of vaccination（接种）given by the doctors.