i didn't believe they could do the work 是否定转移吗否定转移,要求主句是什么时态

i didn't believe they could do the work 是否定转移吗否定转移,要求主句是什么时态
i didn't believe they could do the work 是否定转移吗
否定转移,要求主句是什么时态

i didn't believe they could do the work 是否定转移吗否定转移,要求主句是什么时态
是