[解析]
(1)细节理解题。根据第一段The people who use it are young and old,short and tall,thin and fat.It is everybody's second language.It is easy to understand,although you can't hear it.It is sign language.(使用它的人有年轻人也有老年人,矮有高,瘦有胖。它是每个人的第二语言。虽然你听不见,但很容易理解。这是手语。)可知,手语是一种不用言语表达思想的方式。故选B。
(2)细节理解题。根据第二段When you raise your hand in class,you are saying, "Please ask me,I think I know the correct answer."(当你在课堂上举手时,你在说,"请问我,我想我知道正确答案"。)可知,如果你想表达"请问我,我想我知道正确答案",你应当举手。故选A。
(3)D推理判断题。根据第三段Babies who can't talk can point at things.They are using sign language.(不会说话的婴儿可以指着东西。他们在使用手语。)以及第四段And the deaf people can read and understand them.Soon there were schools for the deaf in many countries.The only university for the deaf is Gallaudet College in Washington,D.C.(聋哑人可以阅读和理解它们。很快,许多国家都有了聋人学校。唯一的聋人大学是华盛顿特区的加劳德特学院。)以及One finger in front of an actor's mouth can mean quiet,you can talk to people who are behind windows that are closed.And when you go swimming with your friends,you can have conversations under the water.(一个手指放在演员的嘴前意味着安静,你可以和窗户后面关着的人说话。当你和朋友去游泳的时候,你们可以在水下交谈。)可知,通过阅读文章,可以总结出:手语每天都在使用,其广泛地应用于人们的生活各处。故选D。
(4)标题归纳题。根据第一段There is one language that is used in every country in the world.The people who use it are young and old,short and tall,thin and fat.It is everybody's second language.It is easy to understand,although you can't hear it.It is sign language.(世界上每个国家都使用一种语言。使用它的人有年轻的也有年老的,有矮的也有高的,有瘦的也有胖的。它是每个人的第二语言。它很容易理解,虽然你听不见。那就是手语。)可知,文章主要是介绍手语。因此C项"手语介绍"可以作为本文的最佳标题。故选C。