问题 选择题

将V1 mL 1.00 mol/L HCl溶液和V2 mL未知浓度的NaOH溶液混合均匀后测量并记录溶液温度,实验结果如图所示(实验中始终保持V1+V2=50 mL).下列叙述正确的是

[ ]

A.做该实验时环境温度为22℃

B.该实验表明化学能可以转化为热能

C.NaOH溶液的浓度约为1.00 mol/L

D.该实验表明有水生成的反应都是放热反应

答案

答案:B

阅读理解与欣赏
阅读理解

阅读理解。

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项,选项中有两项为多余选项.注意:E=AB; F=AC; G=AD

                                          Autumn blues? Let the sunshine in.

     Falling leaves, whithering flowers, cold winds, faint sunshine.    1   Spirits can be low.

     People who suffer from "the autumn blues" often are extremely exhausted, lack energy, need more

sleep, feel increased appetite and gain weight.

     "The exact cause of this condition, often called seasonal depression or seasonal affective disorder

(SAD), is not known yet," says Chen Jue, associate professor at Shanghai Mental Health Center. "But

recent studies indicate that weather change is influential and strongly suggest that this condition is caused

by changes in the availability of sunlight."

     One theory is that with decreased exposure to sunlight, the biological clock that regulates(调节)

mood, sleep, and hormones is delayed, running more slowly in winter.   2   Another theory is that brain

chemicals that transmit information between nerves may be altered(改变) in individuals with SAD. It is

believed that exposure to light can correct these imbalances.

      "  3   Remember, spring always lives in your heart." Chen says.

      Here are some tips to deal with autumn depression.

      1.Go outdoors and get some sunlight. More around. Fresh air and exercise improve the respiratory

( 呼吸) system and blood circulation and regulate the nerves system. Thus, exercise is calming and

relieving one's mood.

    2.Relax at work. Stretch, breathe deeply. Take a tea break. Think of your next vacation.

    3.  4   Chocolate and sugar raise the spirits.

    4. Look at bright colors, such as red and orange.

    5.  5   Blooming plants are cheering

    6.Call friends or family when you feel lonely or depressed. Recall some happy memories.

     A.Exposure to light may reset the biological clock.

     B.Decorate your room and work space with flowers.

     C.It is a sad season, but you can try to make it happy.

     D.That is the way you can use to lighten yourself.

     E.Keep a chocolate bar in your pocket.

     F.For many people, late autumn can be a season of gloom and depression.

     G.Autumn always gives us a beautiful scene.