question: OPTIONS:
- yes
- no
In suffix pairs, a different infinitive ending is added to the perfective stem; for example, the perfective verbs koupit (to buy) and prodat (to sell) have the imperfective forms kupovat and prodavat.
What is added to the ending in suffix pairs?

answer: yes

[Q]: Sentence: He was most unwilling to accept the dignity, for he clearly foresaw the difficulties in which it would involve him. Question: Was Saint Athanasius willing or unwilling to fill the vacancy? OPTIONS:
- yes
- no
++++++++++
[A]: yes

Q: Does "According to Forbes magazine, San Diego was the ninth-safest city in the top 10 list of safest cities in the U.S. in 2010." provide a valid answer to "What did Business Insider call San Diego in 2013?"?
OPTIONS:
- yes
- no
A: no

Problem: Does "State laws have dramatically diverged in the centuries since independence, to the extent that the United States cannot be regarded as one legal system as to the majority of types of law traditionally under state control, but must be regarded as 50 separate systems of tort law, family law, property law, contract law, criminal law, and so on." answer the question "Which ranch applies, interprets, and occasionally overturns both state statutes and regulations?" OPTIONS:
- yes
- no

A: no

Does the sentence "Two of the lions are found above the handles on either side of the trophy the third is symbolised by the captain of the title winning team as he raises the trophy, and its gold crown, above his head at the end of the season." provide a valid answer to the question "What do the ribbons on the trophy mean?" OPTIONS:
- yes
- no

A: no

Does the sentence "Yet Serbian dominance was short-lived; the Serbian army led by the Lazar Hrebljevanovic was defeated by the Ottomans at the Battle of Kosovo in 1389, where most of the Serbian nobility was killed and the south of the country came under Ottoman occupation, as much of southern Bulgaria had become Ottoman territory in 1371." provide a valid answer to the question "What event resulted in the triumph of Serbia over Bulgaria in 1330?" OPTIONS:
- yes
- no

A:
no