your letter, I am pleased to tell you that you are to receive the answer by the end of this week.
A. Concerned about
B. Concerning
C. Concerning with
D. Concerned
网友回答
A. Concerned about
(答案→)B. Concerning
C. Concerning with
D. Concerned
解析：Concerning为介词“关于，有关”比about正式。句意为“关于你的信件我很高兴的告诉你这个周末你会得到答复”