他们正在干什么?用英语怎么说?

"What are they doing?" is the English equivalent to "他们正在干什么?"

Source: This is a basic English question that is used to ask about the actions or activities of a person or group of people.

Examples:

What are they doing? (他们正在干什么?)
Can you tell me what they're doing? (你能告诉我他们在做什么吗?)
I wonder what they're up to. (我想知道他们正在做什么)

Translations:

他们正在干什么？
你能告诉我他们在做什么吗？
我想知道他们正在做什么。