it's said that you don't have school during your National day holidayNo,we usually have seven days off为什么回答是No而不是yes

it's said that you don't have school during your National day holiday
No,we usually have seven days off
为什么回答是No而不是yes

如果后面的延续回答是肯定的时候,就应该用Yes回答,否则就应该用No来回答.
比如说：A:Aren't you going fishing today?
B :Yes,I am.(或者是：No,I am not.)