It means you need some help (mostly used to tell someone they need mental help)
Answer: stimulus
The students reaction is explained by the theory of classical conditioning first coined by Ivan Pavlov. The students are conditioned to associate the doer closing with the pop quiz and respond accordingly. Pavlov used dogs and their response to ringing a bell every time their food was served, after a some conditioning the dogs would salivate at the sound of the bell regardless of whether or not food was present. The bell was the stimulus.
<span>A. It established federal emissions standards
</span>The enactment of the Clean Air Act of 1970 (1970 CAA) resulted in a major shift in the federal government's role in air pollution<span> control. This legislation authorized the development of comprehensive federal and state regulations to limit </span>emissions<span> from both stationary (industrial) sources and mobile sources.</span>
