阿摩線上測驗
21. It's a simple act of ________to always hold the door for the person behind you.
(A) courtesy
(B) frequency
(C) harvest
(D) impulse
答案：登入後查看
統計： A(18), B(2), C(2), D(4), E(0) #3988848
統計： A(18), B(2), C(2), D(4), E(0) #3988848
