Working memory, or short-term memory， involves the ability to hold and use information in the immediate future. ____ 31____ is only held in working memory for about 20 seconds. The challenge that students____32____is to move information from their working memories into their long-term memories. If they don’t do this in about the first few minutes after receiving the information， that information can be lost. To keep this newly learned material from____33____away,it needs to enter the network of the brain’s wiring .
After repeated practice， working memories are set down as permanent neuronal (神经的) circuits____34____to be activated(激活) when the information is needed. When a memory has been recalled____35____ its neuronal circuits are more highly developed because of their repeated activation.
____36____exercising a muscle， these circuits then become more efficient and easier to access and activate. Practice results____37____ repeated stimulation of the memory circuit. Like hikers along a path ____38____ eventually leave a depression in the road， repeated practice stimulates cells in the memory circuit such that the circuit is reinforced and becomes ____39____. This means it can be quickly turned from off to on， and switched. ____40____through a variety of cues coming in from the senses.