Question

of the planets earth, venus, and mars, are in the habitable zone. considering only distance from the sun, would be the hottest of the three planets.

Explanation:

1. For the first blank: The habitable zone (or Goldilocks zone) around a star is the region where conditions are suitable for liquid water to exist on a planet's surface. Earth is in the habitable zone. Venus is too close (has a runaway greenhouse effect), and Mars is on the outer edge but generally, Earth is considered in the habitable zone (sometimes Mars is also considered marginally, but the main one among these three is Earth; however, actually, Earth is in the habitable zone, and sometimes Mars is considered to have had conditions in the past, but for the three, Earth is the primary one in the habitable zone. Wait, actually, the habitable zone for our Sun includes Earth and Mars (marginally) and Venus is too close. But the standard answer here is likely "Earth" (or "Earth and Mars" but more commonly Earth is the clear one in the habitable zone among these three in basic astronomy).
2. For the second blank: The closer a planet is to the Sun, the more solar radiation it receives, so the hotter it is (considering only distance). Among Earth, Venus, and Mars, Venus is the closest to the Sun (Venus is closer than Earth, Earth is closer than Mars). So Venus would be the hottest when considering only distance from the Sun.

Answer:

First blank: Earth
Second blank: Venus