31. We made ______ to the practices of other companies when developing our procedures.
(A) refer
(B) referral
(C) referring
(D) reference
答案:登入後查看
統計: A(4), B(0), C(5), D(8), E(0) #3887978
統計: A(4), B(0), C(5), D(8), E(0) #3887978