Definition: the number 1 Level: A1
你有三个包，而我只有一个。
You have three bags and I only have ___one.
今天早上来了四个包裹，但只有一个是给马克的。
Four packages came this morning, but only ___one was for Mark.
涂一面，让它干，然后涂另一面。
Paint ___one side, leave it to dry, and then paint the other.
