Sentence Analysis:
- "It was (i) $\qquad$ portent when the speaker tripped on his way to the dais."
- A "portent" is a sign or warning of something, often something momentous or calamitous.
- Tripping on the way to the dais (a platform) would generally be seen as a bad sign.
- "Fortuitously, however, an immediate droll remark (ii) $\qquad$ the speaker's rapport with the crowd."
- "Fortuitously" means by chance, fortunately. The "however" indicates a contrast to the initial negative event.
- "Droll remark" means a humorous or amusing comment.
- This remark had a positive effect on the speaker's "rapport" (a close and harmonious relationship) with the crowd.

Analyzing Blank (i):

We need a word that describes a bad or unfavorable sign.
- A. an augural: "Augural" relates to an augur, someone who predicts the future. It means "foretelling or characteristic of an omen," and can be neutral or positive. It doesn't inherently imply a bad sign.
- B. pernicious: Means having a harmful effect, especially in a gradual or subtle way. While it's negative, it doesn't directly describe a "portent" as a bad sign; it describes something causing harm.
- C. an inauspicious: "Inauspicious" means not conducive to success; unpromising; unlucky. This perfectly fits the idea of a bad or unfavorable sign.

Analyzing Blank (ii):

We need a word that shows a positive effect on the speaker's rapport with the crowd, contrasting with the negative start. The droll remark made things better.
- D. buoyed: "Buoyed" means made (someone) feel more cheerful or confident. If rapport is buoyed, it means it was lifted or improved, which is a positive outcome.
- E. served: "Served" means performed a function or role. "Served the speaker's rapport" is too neutral and doesn't convey the positive recovery implied by "fortuitously, however."
- F. alleviated: "Alleviated" means made (suffering, deficiency, or a problem) less severe. While the remark alleviated the awkwardness or embarrassment of the trip, it more directly improved the rapport, rather than just making it "less severe." "Buoyed" speaks more directly to strengthening the rapport.

Conclusion:
- For Blank (i), C. an inauspicious is the best fit.
- For Blank (ii), D. buoyed is the best fit.

The completed sentence would read: "It was an inauspicious portent when the speaker tripped on his way to the dais. Fortuitously, however, an immediate droll remark buoyed the speaker's rapport with the crowd."