In his experiment, dogs were shown two covered containers. One held a treat.

在他的实验中，他把两个有盖的箱子放在几只狗的面前，其中一个箱子里放着食物，另个则空空如也。

youdao

In his experiment, dogs were shown two covered containers. One held a treat.

在他的实验中，他把两个有盖的箱子放在几只狗的面前，其中一个箱子里放着食物，另个则空空如也。

youdao