Graduate students enter the venue before the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year. (Photos: Xinhua)

Graduate students attend the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

Graduate students take a selfie before the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

Graduate students pose for photos on campus after the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

Graduate students from China pose for photos on campus after the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

Graduate students attend the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

Graduate students attend the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

Graduate students from China pose for photos before the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

Graduate students attend the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

Photo taken on May 22, 2019 shows the Columbia University Commencement ceremony in New York, the United States. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

A graduate student looks at the buildings on campus after the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

Graduate students attend the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

A graduate student holds her dog during the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

Graduate students from China attend the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

Graduate students attend the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

Graduate students from China attend the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

Graduate students pose for photos on campus after the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

Graduate students attend the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.

Graduate students attend the Columbia University Commencement ceremony in New York, the United States, May 22, 2019. The Columbia University Commencement ceremony of the 265th academic year took place on Wednesday. More than 17,000 students from Columbia's 18 schools and affiliates graduated this year.