1. guinea pig
They're asking for students to be guinea pigs in their research into the common cold.
We know that a hungry fox will break into hutches and eat pet rabbits and guinea pigs.
Can't you understant this? He used you as a guinea pig.
David would happily be a guinea pig for the pill.
Did you know that guinea pigs, like the ones people keep in cages as pets, actually live in the wild in South America?
I was a guinea pig.
I have three guinea pigs which I keep in a hutch.
英語 "という言葉cochon d'Inde"(guinea pig)集合で発生します。
Animal de compagnie en anglais