If the temperature drops below a certain level it sends a signal, 'turn on the heat', and that signal stays on until it gets a negative signal to turn off.

如果温度降到一定程度以下时,探测器会发送一个信号,打开加热器,直到加热器再收到关闭的信号,它就会一直开着

耶鲁公开课 - 生物医学工程探索课程节选

Those same estimates say that if you could turn that around, that if the world could eat the recommended level of fruits and vegetables, that you'd reduce the prevalence of heart disease by 31%.

反过来说就是,如果大家都能食用适量的水果和蔬菜,那心脏病的普遍性将降低31%

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

The European elections saw a dismal level of turn out.

BBC: Charles Kennedy: A party of government

Sorenstam sunk birdies to claim the first two holes against Young but dropped back to be level at the turn before winning at 10, 12 and 13 to close out the contest.

BBC: SPORT | Golf | Sorenstam & Wie advance with ease

He would turn, level the pellet gun, intone: Are you aware of the usage of this human implement?

NEWYORKER: Tenth of December