Today we'll talk about reading. When we read a text, our eyes move across a page in short, quick movements. We recognize words usually when our eyes still fixate(停留, 凝视). Each time they fixate, we see a group of words. This is known as the recognition span or the visual span. The length of time for which the eyes stop varies from person to person. It also varies within any person according to his purpose in reading and his familiarity with the text. In addition, it can be affected by such factors as lighting and tiredness.
Unfortunately, in the past, many reading improvement courses have concentrated too much on how our eyes move across the page. As a result of this misleading emphasis on the purely visual aspects of reading, many exercises have been designed to train the eyes to see more words at one fixation. For example, in some exercises, words are flashed on to a screen for a tenth of a second. One of the exercises has required students to fix their eyes on some central point, taking in the words on either side. Such word patterns are often formed in the shape of pyramids, so the reader takes in more and more words at each successive（连续的）fixation. All these exercises are very clever, but it's one thing to improve a person's ability to see words and quite another thing to improve his ability to read a text efficiently. Reading requires the ability to understand the relationship between words. Consequently, for these reasons, many experts have now begun to question the usefulness of eye training, especially since any approach which trains a person to read isolated(孤立的) words and phrases would seem unlikely to help him in reading a continuous text.
The time of the recognition span can be affected by the following factors except _______.

A．1ighting and tiredness

B．one's purpose in reading

C．the length of a group of words

D．one's familiarity with the text

What does the author mean by the underlined sentence in the second paragraph?

A．The ability to see words is not needed for an efficient reading.

B．The reading exercises mentioned are of little help to an efficient reading.

C．The reading exercises mentioned can help improve reading.

D．The reading exercises mentioned have done a great job so far.

The author may believe that reading ______________.

A．demands a deeply-participating mind

B．requires a reader to see words more quickly

C．requires a reader to take in more words at each fixation

D．demands more eyes than mind

The tune of the author in writing this text is ___________.

A．supportive	B．neutral
C．critical	D．optimistic