In English, you can say "Good afternoon" to greet people in the afternoon. The phrase "Good afternoon" is a way to wish someone well during the time of day between noon and evening. It is a polite and common way to greet people in the afternoon. Here are some examples of how you can use this phrase in conversation:

"Good afternoon, how are you?"

"Good afternoon, it's nice to see you again."

"Good afternoon, can I help you with anything?"

In Chinese, "Good afternoon" can be translated as 下午好 (xià wǔ hǎo). The phrase "Good afternoon" comes from the custom of wishing someone well at different times of the day, with "good" being a way to express well-wishes and "afternoon" referring to the time of day.