搜题请搜索小程序“爱下问搜题”
问题 问答题 简答题

进局光缆成端的光电特性有什么要求？

答案

参考答案：

（1）光纤的成端接头的连接应在监测条件下进行；连接损耗应控制在较小的范围，避免过大的连接损耗出现。

（2）有铜导线的光缆，在连接前后均应进行直流参数的测量，确保成端后电气特性良好，成端后耐压一般不再测量。

单项选择题

When a consumer finds that something he or she bought is faulty or in some other way does not live up to what the producer says for it, the first step is to present the warranty, or any other records that might help, at the store of buying. In most cases, this action will produce results. However, if it does not, there are various means the consumer may use to gain satisfaction.
A simple and common method used by many consumers is to complain directly to the store manager. In general, the "higher up" the consumer takes his or her complaint, the faster he or she can expect it to be settled. In such a case, it is usually settled in the consumer’s favour taking it as true that he or she has a just right.
Consumers should complain in person whenever possible, but if they cannot get to the place of buying, it is acceptable to phone or write the complaint in a letter.
Complaining is usually most effective when it is done politely but firmly and especially when the consumer can show clearly what is wrong with what was bought in question. If this cannot be done, the consumer will succeed best by presenting specific information as to what is wrong, rather than by making general statements. For example, "The left speaker does not work at all and the sound coming out of the right one is unclear" is better than "This stereo does not work. "
The store manager may advise the consumer to write to the producer, if so, the consumer should do this, setting the complaint as politely and as firmly as possible. But if a polite complaint does not achieve the expected result, the consumer can go a step further. He or she can threaten to take the seller to court or report the seller to a public organization responsible for protecting consumers rights.

The passage tells us ______.

A．how to make the complaint have a good effect
B．how to settle a consumer’s complaint
C．how to avoid buying something wrong
D．how to deal with complaints from consumers
查看答案
选择题

下列物质，露置在空气中质量不会改变的是（　　）

A．NaCl

B．浓H2SO4

C．浓HCl

D．NaOH
查看答案