The answers are C and D.

Blank (i) --> In this context, the sentence is introducing the idea of continuing in a course of action despite challenges.
A. ambition: While ambition involves setting and pursuing goals, it doesn't directly convey the idea of persisting or sticking to tasks despite challenges. This option is not the best fit for completing the sentence.
B. creativity: Creativity involves generating new ideas and solutions, but it doesn't necessarily imply the persistence or stick-to-it virtue mentioned in the sentence. It's not the most appropriate choice in this context.
C. persistence: This word aligns well with the idea of sticking to tasks or goals despite challenges. It conveys the notion of enduring effort and determination.

Blank (ii) --> Here, the sentence introduces a contrast, suggesting that persistence may seem like the direct opposite or contrast to another quality.
D. antithesis of: Antithesis means the direct opposite or contrast. In the context, "antithesis of" fits well to convey that persistence may sound like the direct opposite or contrast to novelty seeking. It sets up the contrast between two qualities.
E. foundation for: Foundation for doesn't capture the contrast between persistence and novelty seeking. It implies a more supportive relationship, which is not the intended meaning in this context.
F. precursor to: Precursor to implies something that comes before or leads to another. In this context, it doesn't effectively convey the contrast between persistence and novelty seeking.