单选题：Read With Greater Speed　　Do you have difficulty reading in c

　　Read With Greater Speed
　　Do you have difficulty reading in class If so, a special reading program that helps match sounds with letters could speed up your brain.
　　At least one out of every five elementary school students in the US has trouble learning to read, even when the students are good at other subjects._______（46）
　　Researchers from Yale University, US, studied a group of children from New York and Connecticut State. As part of the study, 37 struggling readers received special tutoring.
　　Every day, instructors worked with them on recognizing how written letters represent units of sound called phonemes （音素）._______（47）
　　By the end of the school year, these children could read faster than before. They also made fewer mistakes, and understood more of what they read than they could earlier in the year.
　　As part of their study, the researchers used a special machine to take action photos of the students' brains.
_______（48） This is the same part of the brain that becomes active when good readers read. This activated brain area appears to include a structure that helps people　recognize familiar written words quickly. In lower level readers, this structure remains inactive.
　　A year later, the brain structure was still working hard in the students who had gone through the special tutoring, and they continued to do well in reading tests._______（49）
　　However, some researchers still doubt the study._______（50）
A．Many adults are interested in matching sounds with letters.
B．The students also practiced reading aloud and spelling.
C．The biggest challenge for many of these kids, scientists say, is matching sounds with letters.
D．Another group in the study who went through a more traditional reading program didn't show the same progress.
E．The pictures showed an increase in activity in the back of the brain on the left side.
F．They believe that reading without making any noise or linking words to sounds is more efficient.
请选择（46）处的最佳答案．