It seems to be strange to you there is a blind spot(盲点)on the eyes,Here is an interesting experiment(实验)that can make something disappear,when one eye is open.
Make a card about the size of a postcard and write two English letters L and R on it,L on the left and R on the right.First,hold the card about 80 cm away and you see both the letters.Then close your right eye and look at the letter R only with your left eye.And now,as you move the card slowly towards you,you’ll find the letter L disappearing.But if you move the card nearer to your face,the letter will be seen again.Now do the same experiment with your left eye closed,you’ll find the letter R disappearing.
Why does the letter disappear? It is because there is a blind spot on the eye.When the image(影像)of the letter falls on the blind spot,it won’t be seen.That is why either of the letters
disappears.The writer of the passage thinks that __________ there is a blind spot on the eye.
A.few people know | B.no one knows |
C.only you know | D.all the people know |
You fail to see the letter L in the experiment because __________.
A.your eyes are poor | B.its image falls on the blind spot |
C.your left eye is not open | D.you move it close to your eye |
In which order(顺序)should you do the experiment?
①Hold the card ② Move the card nearer
③ Close your right eye ④ write two English letter
⑤ Look at the letter R ⑥ Make a card
A.④⑥①②③⑤ | B.①③⑥④⑤② |
C.⑥①④③②⑤ | D.⑥④①③⑤② |
.The passage mainly(主要)tells us_________.
A.how to find the blind spot |
B.an interesting experiment |
C.where the blind spot is |
D.there is a blind spot on the eyes. |