Along with the letter was his promise he would visit me this ing Christmas.
A. which
B. that
C. what
D. whether
网友回答
A. which
(答案→)B. that
C. what
D. whether
解析：考查同位语从句。同位语从句That he would visit me this ing Christmas解释promise的内容，that引导起同位语从句，只起连接作用。句意：随同他的信而来的是他的诺言，他会在即将来临的圣诞节期间来看我。