When rats are trained to self-administer by pushing a lever, they'll push it over and over again — even hundreds of times — to get a single dose of cocaine.

当老鼠被训练到能够通过推动操作杆来自己施用药物时，它们就会反复不断的推——甚至上百次——来获得一剂量的可卡因。

youdao

But I know from the lever rule that if I do that, I'm going to have precious little material over here.

但是从杠杆原理知道，如果我这样做了，最后得到的量很少。

youdao

I just don't get excited over the idea of yet another thing I could do if I pulled the right lever or set the right program.

我并没有因为目前的我能做的另一件事如果我能拉动右杠杆或者设置正确的程序变得激动。

youdao

And in the charged atmosphere after this bail-out meddling politicians, as part-owners, would have a tempting lever over the banks.

ECONOMIST: America's bail-out plan

In the search for a lever over the Sri Lankan government's policy, many eyes have lighted on an unlikely instrument: Sri Lanka's clothing exports.

ECONOMIST: Sri Lanka's triumphant government

Any Cherokee chief has a powerful lever over tribal members who live in Oklahoma, since many of them receive salaries from either the tribal government or Cherokee-owned businesses.

ECONOMIST: The Cherokee nation