_____ was caused by breathing impure air was once a common belief.
_____ was caused by breathing impure air was once a common belief.
Explanation
Malaria was caused by breathing impure air was once a common belief.
ملیریا سانس لینے کی ناپاک ہوا کی وجہ سے ہوا تھا جب ایک بار ایک عام عقیدہ تھا۔
Malaria directly refers to the subject of the belief in the sentence.