The exhibition is/was held twice every year?哪个对?

The exhibition is/was held twice every year?哪个对?
The exhibition is/was held twice every year?哪个对?

The exhibition is/was held twice every year?哪个对?
都对...
was是过去...
is是现在

都对，看情况

The exhibition is held twice every year.表客观事实