Do you wake up every day feeling too tired, or even upset? If so, then a new alarm clock could be just for you. The clock, called SleepSmart, measures your sleep cycle, and waits【C1】______ you to be in your lightest phase of sleep【C2】______ rousing you. Its makers say that should【C3】______ you wake up feeling refreshed every morning. As you sleep you pass【C4】______ a sequence of sleep states—light sleep, deep sleep and REM (rapid eye movement) sleep—that【C5】______ approximately every 90 minutes. The point in that cycle at which you wake can【C6】______ how you feel later, and may【C7】______ have a greater impact than how much or little you have slept. Being roused during a light phase【C8】______ you are more likely to wake up energetic. SleepSmart【C9】______ the distinct pattern of brain waves【C10】______ during each phase of sleep, via a headband equipped【C11】______ electrodes(电极)and a microprocessor. This measures the electrical activity of the wearer' s brain, in much the【C12】______ way as some machines used for medical and research【C13】______ , and communicates wirelessly with a clock unit near the bed. You【C14】______ the clock with the latest time at【C15】______ you want to be wakened, and it【C16】______ duly(适时地) wakes you during the last light sleep phase before that. The【C17】______ was invented by a group of students at Brown University in Rhode Island【C18】______ a friend complained of waking up tired and performing poorly on a test.【C19】______ sleep-deprived people ourselves, we started thinking of【C20】______ to do about it, " says Eric Shashoua, a recent college graduate and now chief executive officer of Axon Sleep Research Laboratories, a company created by the students to develop their idea.

【正确答案】 A

【答案解析】解析：动词辨析。本句的意思是“制造商承诺它会让你每天早晨醒来都会感觉精神振作”。ensure“保证，确保”，强调使某一行为或结果得以确保，符合语境，故A项为正确答案。assure意为“使确信；向……保证”，着重指信心；require意为“需要，要求”，request意为“请求，要求”。

【正确答案】 D

【答案解析】解析：动词辨析。只有repeat能够更好地贴合句意，“这些睡眠阶段每90分钟重复一次”，而且后面一句in that cycle也暗示前面提及的现象是一个循环过程，故D项为正确答案。reveal意为“揭示，显示”，reverse意为“反转，颠倒”，resume意为“(中断后)重新开始，恢复”。

【正确答案】 B

【答案解析】解析：动词辨析。本句中，how you feel later和have a greater impact是并列的谓语成分，因此所选的动词应该和impact具有相近的意思，B项affect意为“影响”，符合语境，为正确答案。effect作动词时表示“实现，使生效”，reflect意为“反映，反射”，perfect作动词时表示“使完美”，均不符合题意。

【正确答案】 B

【答案解析】解析：动词辨析。during each phase of sleep作后置定语修饰brain waves，brain waves 作所填词的逻辑宾语。故首先可以排除不及物动词proceed“继续进行”和progress“进步，前进”，pronounce“发音；宣布”虽可作及物动词，但是不能用brain waves作宾语。只有produce“生产，产生”能与brain waves构成搭配，故B项为正确答案。

【正确答案】 B

【答案解析】解析：动词辨析。本句句意是“你把闹钟调到你想要被叫醒的最近的时间”。program…with为习惯表达，意为“为……编制／设定(程序等)”，故B项为正确答案。prompt意为“促使，推动”；plug意为“塞住；接通电源”；plan意为“计划”，一般不能和with连用。

【正确答案】 C

【答案解析】解析：名词辨析。所填词作invented的宾语，是对前面内容的概括，前面说明了SleepSmart的设计原理和作用，C项concept“概念”最符合语境，故为正确答案。claim意为“要求；声称”，conclusion意为“结论”，explanation意为“解释”，均不能作invented的宾语。