题目内容：

If you want to learn anything at school, you need to listen to your teachers. Unfortunately, millions of kids can’t hear what their teachers are saying. And it’s not because these students are goofing off. Often, it’s the room’s fault. Building architecture and building design can create echo(回声)-filled classrooms that make hearing difficult.

Children with hearing impairments（损伤）suffer most from noisy classrooms. They sometimes can’t hear questions that other students ask in class. Compared with kids with healthy hearing, they have a harder time picking up new vocabulary words by hearing them in talking.

Even kids with normal hearing have a harder time in the classroom when there’s too much noise. Younger children in particular have trouble separating important sounds – like a teacher’s voice – from background noise. Kids with learning disabilities and speech impediments（障碍）and kids for whom English is a second language also have a harder time learning in noisy situations.

In recent years, scientists who study sound have been asking schools to reduce background noise, which may include loud air-conditioners and pipes. They’re also targeting outdoor noises, such as highway traffic. Noise reduction is a big deal. Why? Because quieter classrooms might make you smarter by letting you hear your lessons better.

“It’s so obvious that we should have quiet rooms that allow for access to the lesson,” says Dan Ostergren, a hearing scientist. “Sometimes it surprises me that we spend so much time discussing this topic. I just want to go. Why is this hard for anyone to grasp?”

1.The underlined part “goofing off” in the first paragraph can be replaced by “     ”.

A．lazy

B．intelligent

C．sleepy

D．foolish

2.Who is most affected by noisy classrooms?

A．Children with learning disabilities.

B．Children with speech impairments.

C．Children with hearing impediments.

D．Children with normal hearing.

3.Why should noise be reduced in classrooms?

A．Quiet classrooms are suitable for kids to have discussions.

B．Quiet classrooms help kids recover from hearig impairments.

C．Kids can’t separate sounds of air-conditioners and pipes.

D．Kids can become smarter after hearing lessons better.

4.What would be the best title for the passage?

A．Classroom design	B．Noisy classrooms
C．The sense of hearing	D．Disabled kids