During a transit , Mars would be visible from Earth as a small black disc moving over the face of the sun .
During a transit , Mars would be visible from Earth as a small black disc moving across the face of the Sun .
During a transit , Mars would be visible from Earth as a small black disc moving across the face of the Sun .
写出该句子的释义版本: During a transit , Mars would be visible from Earth as a small black disc moving over the face of the sun . 输出: