I made a promise to myself this year my first year in high school would be different.A.

问题补充：

I made a promise to myself this year, my first year in high school, would be different.

A. whether

B. what

C. that

D. how

答案：

A. whether

B. what

C. that

D. how

解析：that引导同位语从句，在从句中不做句子成分，补充说明同位语promise的内容。