1. pairs
I bought two pairs of trousers.
Tom hung the three pairs of wet jeans on the clothesline.
The teacher asked the students to practice the dialogue in pairs.
Shoes are sold in pairs.
I've worn out two pairs of shoes this year.
My mother bought me two pairs of pants last Sunday.
In poker, three of a kind beats two pairs.
The hosiery factory produces 600,000 pairs of socks a day.
The king of this country isn't a person, but a divine beast with three pairs of wings said to be in far away in the sky.
Their gloves are not in pairs.
There are twelve pairs of cranial nerves.
The children started in pairs.
This is why Tatoeba is multilingual. But not that kind of multilingual. Not the kind where languages are simply being paired up together, and where some pairs are left behind.