My brother and I __________(not be)in ShangHai last month.

问题描述:

My brother and I __________(not be)in ShangHai last month.

正确:weren't
主语为my brother and I,两者,体现复数.故用are;
last month体现一般过去时,故用are的过去式形式were; 其否定式为weren't.