单选题 Which of the following statements best expresses the main idea of the passage?
A. Glass is very useful because it has many unusual qualities.
B. Light signals have changed the use of glass in industry.
C. Glass fibres have reduced the cost of telephone communication.
D. The use of glass fibres to carry telephone message is an interesting new development.

【正确答案】 D

【答案解析】主旨题。本题问下列哪一项陈述最能表达文章的主旨。依据文章第一段第三句“One of the most interesting new uses for glass is in telephone communication.”，而后面的内容均据此铺陈，故可知D项内容是本篇的主题。