单项选择（每题1分）
In his letter was his promise he would spend the Christmas Eve with me.
A. that
B. what
C. which
D. whether
网友回答
(答案→)A. that
B. what
C. which
D. whether
解析：考查同位语从句。Promise“承诺，许诺”，后跟that引导的同位语从句，对promise进行补充说明。句意“他在心中作出承诺，会和我一起过圣诞节平安夜。”故选A。