抗日战争是1937年爆发的。
[误] The Anti-Japanese War was broken out in 1937.
[正] The Aunti-Japanese War broke out in 1937.
注:break out(战争等的爆发)是不及物动词短语,不能用于被动语态。类似的还有 happen, belong,disappear, fail, take place 等。
参考例句:The forecast that war would break out proved true. 战争会爆发的预测被证实了