"The butterfly's (i), though (ii), allowed the entomologist ample time with which to fashion a quick sketch of its markings."

The structure suggests that the butterfly had some characteristic (i) that, despite being (ii), gave the entomologist time to sketch. The word "though" indicates a contrast. So, (ii) might be a quality that seems like it wouldn't allow much time, but actually did because of (i).

We need to choose words that make sense together and with the context.
First, look at Blank (i):
- A. pulchritude: beauty
- B. verisimilitude: appearance of being true or real
- C. quiescence: stillness, inactivity

The characteristic allowed time to sketch. Sketching requires the subject to be still, so "quiescence" (stillness) makes sense. Beauty or verisimilitude might not directly relate to having time to sketch.

Now Blank (ii):
- D. camoufleged (likely a misspelling or variant of "camouflaged": hidden or disguised)
- E. short-lived: lasting only a short time
- F. frigile (likely a misspelling of "fragile": easily broken)

The word "though" sets up a contrast. If the butterfly is still (quiescence), but that stillness is short-lived, that would contrast: even though the stillness didn't last long, it gave enough time to sketch. Alternatively, if it's camouflaged, that might not directly contrast with stillness. Fragile might not contrast well.

So, "quiescence" (stillness) and "short-lived" (brief) make a good pair: the stillness was brief, but it still provided enough time.

Check other options:
- Pulchritude (beauty) though camouflaged? But camouflaged means hidden, so beauty might not be visible, but that doesn't necessarily allow time to sketch.
- Verisimilitude (realism) though short-lived? Not clear.
- Quiescence though fragile? Fragile doesn't contrast with stillness in a way that relates to time for sketching.

Therefore, the best choices are:
Blank (i): C. quiescence
Blank (ii): E. short-lived
The sentence: "The butterfly's quiescence, though short-lived, allowed the entomologist ample time with which to fashion a quick sketch of its markings."

This means the butterfly was still (not moving), and even though this stillness didn't last long, it was enough time to sketch.

Final answer:
Blank (i): C. quiescence
Blank (ii): E. short-lived