Here's the answer:
“喂?”
(wéi?)
Watch a real native speaker say it:
Here's how it sounds in a textbook:
Fun fact: the hundreds of thousands of people learning Chinese with Memrise get this phrase correct 99.05% of the time!
(wéi?)
Fun fact: the hundreds of thousands of people learning Chinese with Memrise get this phrase correct 99.05% of the time!