Why do you think this is happening?
What is happening there?
What's happening?
I think we all know what's happening.
I don't understand what's happening.
I don't know what's happening.
Nothing's happening.
You're probably too young to understand what's happening.
Why is this happening?
Tom didn't know anything about what was happening.
Tom was watching what was happening very carefully.
I can't believe that this is happening. Can someone please tell me that it's a lie?
"What's happening in the cave? I'm curious." "I have no idea."
Even now, from time to time there are aftershocks happening.
There were strange things happening there.
Can you tell me what is happening?
He's not in the least interested in what is happening in the world.
Something funny is always happening in our class.
The probability of this chain of events all happening at once is one in 100 million flights - about once every two months at current levels of air traffic.
Television enables us to know what is happening today.