阅读下面短文，从短文后各题所给的四个选项（A、B、C和D）中，选出可以填入的空白处的最佳选项，并从答题卡上将该选项涂黑。

You have waited 45 minutes for the valuable 10 minutes’ break between classes. But when the bell for the next class rings, you can’t   36   how quickly time has passed.

If you are familiar with this   37  , you’ll know how time flies when you are having fun-and  38   when you are bored. Now scientists have   39   a reason why this is the case.

Scans have shown that patterns of activity in the brain   40   according to how we focus on a task. When we are   41  , we concentrate more on how time is passing. And this makes our brains   42   the clock is ticking more slowly.

In an experiment   43   by a French laboratory, 12 volunteers watched an image   44   

researchers monitored their brain activity.

The volunteers were told to   45   concentrate on how long an image appeared for, then

  46   the color of the image, and thirdly, study both duration and color. The results showed that  47   was more active when the volunteers paid   48   subjects.

It is thought that if the brain is   49   focusing on many aspects of a task, it has to  50  its resources, and pays less attention to the clock.  51 , time passes without us really   52   it, and seems to go quickly. If the brain is not so active, it concentrates its   53   energies on monitoring the passing of time.   54  , time seems to drag.

Next time you feel bored   55  , perhaps you should pay more attention to what the teacher is saying!

A．guess                   B．learn                      C．believe                   D．doubt

A．view                    B．point                      C．scene                   D．experience

A．drags                   B．stops                      C．backs                      D．gains

A．thought over         B．made up                 C．suggested                D．come up with

A．change                 B．develop                  C．grow                      D．slow

A．sleepy                 B．bored                            C．excited                   D．active

A．report                  B．think                      C．decide                    D．see

A．produced              B．carried                    C．tried                       D．performed

A．so                        B．when                      C．while                      D．but

A．partly                 B．quickly                   C．how                       D．first

A．remember           B．focus on                 C．forget                     D．tell apart

A．the researchers    B．the experiment        C．the clock                 D．the brain

A．much attention to                           B．more attention to    

C．attention to many                                        D．attention to more

A．busy                  B．likely                            C．ready                      D．sure

A．focus                 B．gather                     C．reach                      D．spread

A．However            B．Furthermore            C．Therefore                D．Finally

A．recognizing        B．watching                 C．noticing                  D．counting

A．enough               B．full                        C．right                       D．proper

A．In fact                B．As a result                     C．For example            D．Instead

A．in class               B．with work               C．in mind                  D．of lessons

阅读理解

　　Probably you have seen photographs of the Grand Canyon (峡谷), the great valley in the desert country of Arizona. But you must go there yourself to feel its true size and beauty. The Grand Canyon is one of the greatest natural wonders of the world.

　　The Colorado River formed the Grand Canyon over millions of years. Slowly, the river cut down through hard rock. At the same time, the land was rising. Today, the canyon is one and a half kilometers deep and 445 kilometres long. The oldest rocks at the bottom of the canyon are more than 1 billion years old. The width varies from about 200 metres to 29 kilometres across. The rim(边缘) or top of the canyon is about 2,300 metres above sea level on the South Rim, and about 3,000 metres on the other side ,the North Rim As a result, there are different kinds of plants and animals on apposite sides of the canyon The South Rim is dry desert country. The North Rim has tall forests.

　　The canyon looks different at different times of day, and in different seasons and weather. At sunrise and sunset the red, gold, brown, and orange colours of the rocks are especially clear and bright. In winter, the canyon is partly covered with snow.

　　The view from the South Rim of the Grand Canyon is the best. Most visitors come to the South Rim and stay in campgrounds or hotels. Every point along the canyon's edge offers a different view.

　　The North Rim of the Canyon is quieter. It takes all day to drive there from the South Rim because there is only one bridge across the Colorado River. On the way, you go through Navado Indian lands, and a colourful pink desert called“The Painted Desert”.

　　You can walk down into the Grand Canyon, or you can go dawn on the back of a mule(小型电动机车), You can also take a boat trip down the Colorado River, and camp on the beaches at night. But whether you see the Grand Canyon from the top or the bottom, ii will be an experience that you will never forget.

1．The sea level on both sides of the Grand Canyou is ________.

[　　]

2．From the passage we can know that the ________ of the canyon is different at different time.

[　　]

3．If you go to visit the canyon you'd better go to ________.

You have waited 45 minutes for the valuable 10 minutes’ break between classes. But when the bell for the next class rings, you can’t   36   how quickly time has passed.

If you are familiar with this   37  , you’ll know how time flies when you are having fun and  38   when you are bored. Now scientists have   39   a reason why this is the case.

Scans have shown that patterns of activity in the brain   40   according to how we focus on a task. When we are   41  , we concentrate more on how time is passing. And this makes our brains   42   the clock is ticking more slowly.

In an experiment   43   by a French laboratory, 12 volunteers watched an image   44   researchers monitored their brain activity.

The volunteers were told to   45   concentrate on how long an image appeared for, then  46   the color of the image, and thirdly, study both duration and color. The results showed that  47   was more active when the volunteers paid   48   subjects.

It is thought that if the brain is   49   focusing on many aspects of a task, it has to  50  its resources, and pays less attention to the clock.  51 , time passes without us really   52   it, and seems to go quickly. If the brain is not so active, it concentrates its   53   energies on monitoring the passing of time.   54  , time seems to drag.

Next time you feel bored   55  , perhaps you should pay more attention to what the teacher is saying!

A. guess                         B. learn                              C. believe                             D. doubt

A. view                            B. point                              C. scene                               D. experience

 A. drags                       B. stops                             C. backs                               D. gains

 A. thought over                  B. made up                       C. suggested                      D. come up with

A. change                       B. develop                         C. grow                                D. slow

A. sleepy                        B. bored                                      C. excited                            D. active

A. report                        B. think                              C. decide                             D. see

A. produced                  B. carried                          C. tried                                 D. performed

 A. so                             B. when                             C. while                                D. but

A. partly                       B. quickly                           C. how                                  D. first

 A. remember           B. focus on                        C. forget                              D. tell apart

A. the researchers    B. the experiment          C. the clock                         D. the brain

 A. much attention to       B. more attention to      C. attention to many        D. attention to more

 A. busy                       B. likely                              C. ready                               D. sure

A. focus                        B. gather                           C. reach                               D. spread

 A. However              B. Furthermore               C. Therefore                       D. Finally

A. recognizing            B. watching                      C. noticing                           D. counting

A. enough                    B. full                                  C. right                                 D. proper

 A. In fact                    B. As a result                    C. For example                  D. Instead

A. in class                    B. with work                     C. in mind                            D. of lessons