问题 选择题

日常生活中发生的下列变化都属于化学变化的一组是(  )

A.玻璃杯被摔碎,米饭变馊

B.酒精挥发,湿衣服晾干

C.蜡烛燃烧,乒乓球变瘪

D.菜刀生锈,牛奶变酸

答案

A、玻璃杯被摔碎的过程中没有新物质生成,属于物理变化;米饭变馊的过程中有新物质生成,属于化学变化;

B、酒精挥发、湿衣服晾干的过程中没有新物质生成,属于物理变化;

C、蜡烛燃烧生成水和二氧化碳,属于化学变化;乒乓球变瘪的过程中没有新物质生成,属于物理变化;

D、菜刀生锈的过程中生成了新物质铁锈,属于化学变化;牛奶变酸的过程中有新物质生成,属于化学变化.

故选D.

完形填空
A friend of mine met with an accident driving in darkness. His legs were so hurt that he couldn’t move. What was the   1  was he found himself unable to ask for help-his mobile phone went out of   2  as a result of exhausted battery. Nothing could be done but to
  3  in cold wilderness. It was 8 hours later that day broke, and then the   4  of the rescue.
It is almost   5  that he could stand the horror in the darkness for so long. Even more surprising was his  6 : “First of all I checked up my   7  conditions and found myself not in fatal danger. As there was no    8  to call for help, I leaned back in my seat trying my best to keep the wound from  9 .  In this way I dozed (打盹) off.”
His story put an end to my regret for the   10  of an exploration adventure that happened last year. A group of young men   11  to explore a mountain cave and got lost.
  12  to find a way out in the dark cave they were frightened and ran anxiously without a sense of   13 . Finally they fell dead in fear and exhaustion. According to the   14  
people that found them, the place where they got lost was only about 10 meters away from the
  15  of the cave. If they stayed on the spot when they lost their way and tried to   16 
themselves, they would probably sense a faint light glimmering (闪烁) not far away.
Don’t you think that you can compare it with   17  itself? When you meet with obstacles in life and work, you are lost in darkness.   18  you it’s unclear yet and you needn’t put up struggle   19 . It seems to be a negative attitude,  20  a person who can afford to do so must have foresight as well as a great courage in the first place.
小题1:
A.hopelessB.worstC.moreD.best
小题2:
A.serviceB.wayC.orderD.work
小题3:
A.cryB.lieC.waitD.sleep
小题4:
A.delayB.successC.teamD.arrival
小题5:
A.untrueB.unimaginableC.trueD.useless
小题6:
A.planB.decisionC.explanationD.excuse
小题7:
A.physicalB.mentalC.workingD.medical
小题8:
A.methodB.wayC.alternativeD.strength
小题9:
A.rottingB.spreadingC.hurtingD.bleeding
小题10:
A.lossB.failureC.disappointmentD.sadness
小题11:
A.hadB.managedC.triedD.planned
小题12:
A.WillingB.UnableC.DeterminedD.Deciding
小题13:
A.hearingB.sightC.feelingD.direction
小题14:
A.rescueB.villageC.localD.brave
小题15:
A.endB.topC.openingD.side
小题16:
A.saveB.helpC.stopD.calm
小题17:
A.adventureB.workC.lifeD.mankind
小题18:
A.MindB.WatchC.ImagineD.Warn
小题19:
A.reallyB.immediatelyC.carefullyD.hopefully
小题20:
A.andB.soC.butD.while
单项选择题