In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

[Q]: What did the supercapacitors improve?, Context: Last but not least the electric double-layer capacitor (now Supercapacitors) were invented. In 1957 H. Becker developed a "Low voltage electrolytic capacitor with porous carbon electrodes". He believed that the energy was stored as a charge in the carbon pores used in his capacitor as in the pores of the etched foils of electrolytic capacitors. Because the double layer mechanism was not known by him at the time, he wrote in the patent: "It is not known exactly what is taking place in the component if it is used for energy storage, but it leads to an extremely high capacity.".
[A]: electrolytic capacitor


[Q]: Which country has less than 650,000 elevators installed as of January 2008, the United States or China?, Context: As of January 2008, Spain is the nation with the most elevators installed in the world, with 950,000 elevators installed that run more than one hundred million lifts every day, followed by United States with 700,000 elevators installed and China with 610,000 elevators installed since 1949. In Brazil, it is estimated that there are approximately 300,000 elevators currently in operation. The world's largest market for elevators is Italy, with more than 1,629 million euros of sales and 1,224 million euros of internal market.
[A]: China


[Q]: What Christian practice did the emissaries of Vladimir find interesting?, Context: Vladimir had been prince of Novgorod when his father Sviatoslav I died in 972. He was forced to flee to Scandinavia in 976 after his half-brother Yaropolk had murdered his other brother Oleg and taken control of Rus. In Scandinavia, with the help of his relative Earl Håkon Sigurdsson, ruler of Norway, Vladimir assembled a Viking army and reconquered Novgorod and Kiev from Yaropolk. As Prince of Kiev, Vladimir's most notable achievement was the Christianization of Kievan Rus', a process that began in 988. The Primary Chronicle states that when Vladimir had decided to accept a new faith instead of the traditional idol-worship (paganism) of the Slavs, he sent out some of his most valued advisors and warriors as emissaries to different parts of Europe. They visited the Christians of the Latin Rite, the Jews, and the Muslims before finally arriving in Constantinople. They rejected Islam because, among other things, it prohibited the consumption of alcohol, and Judaism because the god of the Jews had permitted his chosen people to be deprived of their country. They found the ceremonies in the Roman church to be dull. But at Constantinople, they were so astounded by the beauty of the cathedral of Hagia Sophia and the liturgical service held there that they made up their minds there and then about the faith they would like to follow. Upon their arrival home, they convinced Vladimir that the faith of the Byzantine Rite was the best choice of all, upon which Vladimir made a journey to Constantinople and arranged to marry Princess Anna, the sister of Byzantine emperor Basil II.
[A]:
the Byzantine Rite