 
<translate> Enwere m ajụjụ m ga-ajụ gị: Ụlọ Elu Willis, nke e wuru dị ka Ụlọ Elu Sears ma ka na-akpọ ya, bụ ụlọ elu dị okpukpu 110 nke dị mita 442.1 n'ịdị elu na Chicago, Illinois. Mgbe e wuchara ya n'afọ 1973, ọ karịrị ụlọ elu World Trade Center dị na New York ka ọ bụrụ ụlọ kachasị elu n'ụwa, aha ọ nwere ihe fọrọ nke nta ka ọ bụrụ afọ 25; ọ nọgidere bụrụ ụlọ kachasị elu na Western Hemisphere ruo mgbe e wuchara ụlọ ọhụrụ na saịtị World Trade Center na 2014. A na-ahụta ụlọ ahụ dị ka ihe dị mkpa maka onye mmebe ya Fazlur Rahman Khan. Ụlọ elu Willis bụ ụlọ nke abụọ kachasị elu na United States na Western Hemisphere - na nke 16 kachasị elu n'ụwa. Ihe karịrị otu nde mmadụ na-eleta ebe a na-anọ ekiri ihe na ya kwa afọ, na-eme ka ọ bụrụ otu n'ime ebe ndị njem nleta kasị ewu ewu na Chicago. E degharịrị aha ụlọ ahụ na 2009 site na Willis Group dị ka akụkụ nke mgbazinye ya na akụkụ nke ụlọ elu ahụ.  Dabere n'ihe e dere n'ebe a, olee aha ụlọ elu ochie ahụ dị na Chicago? Ka anyị buru ụzọ chee echiche: <eng> I got a question for you: The Willis Tower, built as and still commonly referred to as the Sears Tower, is a 110-story, 1,450-foot (442.1 m) skyscraper in Chicago, Illinois. At completion in 1973, it surpassed the World Trade Center towers in New York to become the tallest building in the world, a title it held for nearly 25 years; it remained the tallest building in the Western Hemisphere until the completion of a new building at the World Trade Center site in 2014. The building is considered a seminal achievement for its designer Fazlur Rahman Khan. The Willis Tower is the second-tallest building in the United States and the Western hemisphere -- and the 16th-tallest in the world. More than one million people visit its observation deck each year, making it one of Chicago's most-popular tourist destinations. The structure was renamed in 2009 by the Willis Group as part of its lease on a portion of the tower's space.

Based on this passage, what is the name of the old sears tower in chicago?
Let's think first: 