The time of the recognition span can be affected by the following facts except( )
A、one's familiarity with the text
B、one's purpose in reading
C、the length of a group of words
D、lighting and tiredness
What does the author mean by saying“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 test efficiently.”in the second paragraph? ( )
A、 The ability to see words is not needed when an efficient reading is conducted.
B、The reading exercises mentioned can't help to improve both the ability to see and to comprehend words.
C、The reading exercises mentioned can't help to improve an efficient reading.
D、The reading exercises mentioned have done a great job to improve one's ability to see words.