阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用

括号中单词的正确形式填空，并将答案填写在1-5空格中。

     Now people think that 1            is very important to communicate with others, so radio, telephone

and television are widely used all over the world. When you turn on the radio, you can listen. But when

you use telephone, not only can you listen to others but also you can chat 2             them. 3            ,

you can't see the other one at all. Television is even 4            (good) than both of them. People can

watch TV and listen to it, but you 5             (can) take part in what you see. Perhaps in the near future,

another new kind of phone will come into wider uses in our daily life.

“不入虎穴，焉得虎子”，“要想知道梨子的味道，就得亲口尝一尝”。这两句话体现的哲学原理是( )。

A．实践是认识的来源之一
B．实践是认识发展的动力
C．实践是检验认识正确与否的唯一标准
D．实践是认识的目的