A. 金属加强件、光纤带、松套层绞、填充式、铝-聚乙烯粘结护套通信用室外光缆,包含24根“非零色散位移型”单模光纤。 B. 非金属加强件、光纤带、松套层绞、填充式、铝-聚乙烯粘结护套通信用室外光缆,包含24根“非零色散位移型”单模光纤。 C. 金属加强件、光纤带、松套层绞、填充式、铝-聚乙烯粘结护套通信用室内光缆,包含24根“非零色散位移型”单模光纤。 D. 金属加强件、光纤带、松套层绞、填充式、铝-聚乙烯粘结护套通信用室内光缆,包含24根“零色散位移型”单模光纤。
In this conversation, two students are talking about the courses they will take. Listen carefully, and fill in the gaps with one word or one number.[音频]Ann and Bob are discussing what they need to take for their area of ______.