公园里有很多情侣在散步。

There are many ___couples walking in the park.

我需要买几双袜子，所以拿了两双。

I need to buy some socks, so I picked up a ___couple of pairs.

工程师将两根管道连接在一起以确保水流畅通。

The engineer ___couples the two pipes together to ensure smooth water flow.