Researchers led by New York University neuroscientist Joseph LeDoux recently claimed to be the first scientists to erase a singl

admin2014-04-20  29

问题     Researchers led by New York University neuroscientist Joseph LeDoux recently claimed to be the first scientists to erase a single memory. Working with rats, LeDoux’s team first【B1】______the animals to fear both a beep and a siren【B2】______giving them an electric shock every time either of the tones sounded. Then LeDoux gave half the rats the drug U0126, which is known to【B3】______with memory storage, and replayed the beep【B4】______electric shocks.
    A day later, when LeDoux【B5】______back both tones to the rats, the animals that hadn’t been given the drug were still fearful of both sounds.【B6】______the rats that had been given the memory-blocking drug weren’t【B7】______of the beep, which they had last heard while【B8】______the influence of U0126.
    【B9】______how U0126 exerts its amnesiac effect is【B10】______, but it may block the synthesis of proteins that help strengthen【B11】______between neurons and establish memories. The opportunity for erasure【B12】______during the act of retrieving a memory, because that’s【B13】______the memory is being updated and【B14】______again for long-term storage. " Only those memories that are activated are【B15】______," LeDoux says.
    Drugs like U0126 may someday【B16】______sufferers of traumatic memories. A small group of human studies have been done on a drug called propranolol, which blocks the action of stress neurotransmitters that help【B17】______memories in the brain, but LeDoux’s work shows the【B18】______for greater precision. " You might be able to【B19】______the traumatic impact of memories in people," says LeDoux. " The good news is you wouldn’t be【B20】______off their memory bank. "
【B12】

选项 A、starts
B、occurs
C、arises
D、happens

答案B

解析 动词辨析题。本句讨论记忆阻隔药物发挥作用的时机和条件。由句意可知,当某个记忆检索行为发生的时候,该段记忆易被消除。由此可知正确答案应为[B]occurs“出现”,表示“记忆消除时机出现”。根据主谓搭配关系,易排除[A]starts“开始”,因为opportunity“时机”强调短暂性,瞬时性,没有明确的起终点,不能与starts搭配。[D]happens“发生”,则突出偶然性和出乎意料之意,也不符合文意,故排除。而[C]arises“出现”,虽表面意义相合,但该词多用于困难、问题等逐渐显现,因此也不符合原文意思,故排除。
转载请注明原文地址:https://kaotiyun.com/show/OPO4777K
0

最新回复(0)