You probably have a long mental list of moments and facts you wish you could remember—but

actually you cannot. The good news,【B1】______, is that while such memories may be currently【B2】______, they are not entirely gone, and could theoretically be【B3】______, according to a new brain research. In the study, biologist Jeffrey Johnson【B4】______16 college participants through an FMRI machine (which【B5】______nervous activity via blood flow)to compare brain patterns【B6】______memory formation and recall. First, he showed the students various common words and had them【B7】______a few tasks: say the word backwards in your head,【B8】______its uses, and picture how an artist would【B9】______it. Then, 20 minutes later, after the students re-entered the FMRI machine, Johnson showed them the list of words and asked them to recall【B10】______they could from before. Finally, he compared brain activity from both【B11】______and what he found will surprise you. Using【B12】______is called "pattern analysis" , its possible to【B13】______a unique pattern of brain activity to every individual thing we do. This means that when a participant says the word "apple" backwards the【B14】______pattern of brain activity is different from when he pictures the fruit.【B15】______interestingly, there is close similarity between the pattern that emerges when we【B16】______an activity and when we later recall it. The stronger our memory, the【B17】______the pattern, but as Johnson found, even at a moment【B18】______we cannot remember anything, our nerve cells still fire in a way that【B19】______the activity of when we formed the memory. This【B20】______that sometime in the future we may be able to retrieve the memories we thought wed lost forever.

【B1】

A．although

B．rather

C．though

D．therefore