Take care not to get your shoes ______ in mud．

Quite a few people like traveling, for it can increase their knowledge and broaden their _____．

Look out! Don’t get close to the house, ______ the roof is under repair．

________ Teacher’s Day is just around the corner．I’ll give my teacher a gift, _____ one that is special and unforgettable．

We climbed to the top of the hill, ________．

The lady tried on all the dresses in the stop but found _____ that satisfied her．

Your money could _______ better use instead of _____ idle in the bank．

He is a politician and has a _____ sense of the current affairs all over the country．

His calculation of the result of the exam _______ to the fact, but he failed again．

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 SteepSmart, measures your sleep cycle, and waits ____（36） you to be in your lightest phase of sleep ____（37） rousing you．Its makers say that should ______（38） you wake up feeling refreshed every morning．As you sleep you pass____（39） a sequence of sleep states---light sleep, deep sleep and REM（rapid eye movement） sleep---that ____（40） approximately every 90 minutes．The point in that cycle at which you wake can ____（41） how you feel later, and may ____（42） have a greater impact than how much or little you have slept．Being roused during a light phase ____（43） you are more likely to wake up energetic．

SleepSmart ____（44） the distinct pattern of brain waves _____（45） during each phase of sleep, via a headband equipped _____（46） electrodes and a microprocessor．This measures the electrical activity of the wearer’s brain, in much the ____（47） way as some machines used for medical and research ____（48）, and communicates wirelessly with a clock unit near the bed．You ____（49） the clock with the latest time at _____（50） you want to be wakened, and it _____（51） duly wakes you during the last light sleep phase before that．

The _____（52） was invented by a group of students at Brown University in Rhode Island ____（53） a friend complained of waking up tired and performing poorly on a test．“_____（54） sleep-deprived people ourselves, we started thinking of _____（55） 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 students to develop their idea．