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.