There were billions of flies everywhere. 到处都有许多的苍蝇。
Billions of ads like these are posted on the Internet.
You know that road - we've driven down it a billion times!
There are billions of plastic bags in the cupboard under the sink.
You've got a billion pens - you don't need any more!
I've made billions of cakes like this over the years.
See also: billion