The team built on that skill by associating the lever pressing with a door opening.

团队将“按杠杆”与“开门”联系起来，在此技巧基础上继续实验。

In phase 3, they took a quick break from the lever pressing and introduced each vole to a member of the opposite sex.

在第三阶段，它们暂停按杠杆活动，转去认识异性成员。

The levers and light were set up in exactly the same way except that this time it was only Doris who could see the light indicating which lever to press first.

杠杆和灯光的设置跟原来一样，不过这次只有桃瑞丝能看到灯光并按压杠杆。