As if you needed another reason to hate the gym, it now turns out that exercise can exhaust not only your muscles, but also your eyes. Fear not, however, for coffee can stimulate them again. During【C1】______ exercise, our muscles tire as they run out of fuel and build up waste products. Muscle performance can also be affected by a【C2】______ called " central fatigue" , in which an imbalance in the body's chemical messengers prevents the central nervous system from directing muscle movements【C3】______ It was not known, however, whether central fatigue might also affect motor systems not directly【C4】______ in the exercise itself, such as those that move the eyes. To find out, researchers gave 11 volunteer cyclists a carbohydrate {碳水化合物)【C5】______ either with a moderate dose of caffeine (咖啡因) , which is known to stimulate the central nervous system, or as a placebo (安慰剂) without, during 3 hours of【C6】______ After exercising, the scientists tested the cyclists with eye-tracking cameras to see how well their brains could still【C7】______ their visual system. The team found that exercise reduced the speed of rapid eye movements by about 8% ,【C8】______ their ability to capture new visual information. The caffeine, the equivalent of two strong cups of coffee, was【C9】______ to reverse this effect, with some cyclists even displaying【C10】______ eye movement speeds. So it might be a good idea to get someone else to drive you home after that marathon.
A) cautiously
B) commit
C) control
D) cycling
E) effectively
F) increased
G) involved
H) limited
I) phenomenon
J) preventing
K) sensitive
L) slowing
M) solution
N) sufficient
O) vigorous H) limited
空格前为介词during，空格后为名词exercise，故本空需要填入一个形容词。结合句意可知，做剧烈的运动时，我们的肌肉会疲劳。备选项中只有vigorous(强有力的)符合句意，故答案为O。
空格前为不定冠词a，空格后为动词的过去分词短语作后置定语，故本空需要填入一个名词。结合句意可知，“中枢疲劳”是一种影响肌肉性能的现象。备选项中只有phenomenon(现象)符合句意，故答案为I。
空格前为动宾结构，故本空需要填入一个副词。结合句意可知，当身体的化学信使不平衡时，人体的中枢神经系统不能有效地指挥肌肉活动。备选项中只有effectively(有效地，生效地)符合句意，故答案为E。
空格前为副词directly，空格后为介词in，故本空需要填入一个动词。本句是一个省略结构，完整的句子应该是whether central fatigue might also affect motor systems which are not directly ______ in the exercise itself。结合句意可知，人运动时，许多运动系统没有直接参与到其中。备选项中只有involved(使参加)符合句意，故答案为G。
空格前为名词carbohydrate，空格后为with引导的伴随结构，故本空需要填入一个名词。结合句意可知，研究员为了找出问题的答案，必定会想出解决方法。备选项中只有solution(解决方法)符合句意，故答案为M。
空格前为介词of，故本空需要填入一个名词。由下文After exercising，the scientists tested the cyclists…(运动之后，科学家对这些骑自行车的人进行测试)可知，这应该是一项长达三个小时的骑自行车运动。备选项中只有cycling(骑自行车运动)符合句意，故答案为D。
空格前为情态动词could，空格后为名词，故本空需要填入一个动词。研究人员做该项试验的目的就是为了弄清楚运动导致的中枢疲劳是否也会影响能使眼睛转动的运动系统，所以研究人员进行测试的目的就是为了弄清楚人们运动后大脑还能在多大程度上控制视觉系统。备选项中只有control(控制，管理)符合句意，故答案为C。
空格前为完整的句子The team found that exercise reduced the speed of rapid eye movements by about 8％(研究团队发现运动使得眼球快速移动的速度下降了8％)，而空格后为名词加不定式。又结合句意可知，眼球快速移动的速度下降，应该是不利于眼睛捕捉新的视觉信息，故空格处应填入一个现在分词，表示主句的动作造成的结果。备选项中只有preventing(防止，阻止)符合句意，故答案为J。
空格前为系动词was，空格后为动词不定式标志to，故本空需要填入一个形容词。上文中提到coffee can perk them right up again(喝咖啡可以让你的肌肉和眼睛重新振作起来)，所以，相当于两杯浓咖啡的咖啡因足够彻底改变眼睛疲劳了。备选项中只有sufficient(足够的，充分的)符合句意，故答案为N。
空格前为现在分词displaying，空格后为名词短语，故本空需要填入一个形容词。结合句意可知，相当于两杯浓咖啡的咖啡因足够彻底改变眼睛疲劳了，结合空格所在句中的even可知，有些骑手眼睛转动的速度应该是更快了。备选项中只有increased(增加的)符合句意，故答案为F。