A meeting between presidents: Ukrainian President Volodymyr Zelensky (L) meets with US President Joe Biden (R) in the Oval Office of the White House in Washington, DC on Dec 21, 2022. It’s Zelensky’s first overseas trip since the conflict between Ukraine and Russia broke out in February 2022. Joe Biden pledged (承诺) to offer Zelensky military (军事的) aid totaling 1.85 billion US dollars (about 12.9 billion yuan). With no sign in sight for a quick end to the conflict, governments and economists are now increasingly worried about its economic impact, not only on Ukraine, Russia and other European nations but also on the whole world.