What phrase correctly fills in the blank about past sunbathing habits?

The choice that accurately reflects past sunbathing habits is "I would lie in the sun." This phrase directly conveys the action of sunbathing, which typically involves lying down in the sun to enjoy its warmth and potentially tan the skin.

In the context of discussing habits from the past, the structure "I would..." effectively indicates a repeated or customary action. Therefore, saying "I would lie in the sun" suggests that it was a regular activity for the speaker, capturing the essence of past sunbathing behavior succinctly.

The other options either do not pertain to the action of sunbathing or are inconsistent with the concept of lying in the sun specifically for tanning or relaxation. For instance, lying in the shade contradicts the idea of sunbathing, as it involves avoiding direct sunlight. Sunbathing at night is nonsensical since sun exposure cannot occur after sunset. Lastly, while sleeping in the sun may also suggest being outdoors, it does not convey the intentional act of sunbathing and focuses more on resting rather than actively sunbathing.