中文摘要：

本文研究了几类拓扑性质在有限子序列覆盖映射下的保持性,并给出一个反例回答了如下问题：（1）1-序列商映射是序列覆盖映射吗？（2）序列空间上的开映射是1序列覆盖映射吗？（3）从零维仿紧空间到Lasnev空间的LSC的集值映射一定存在连续选择吗？

英文摘要：

In this paper,some topological properties which are preserved by finite subsequence- covering maps are discussed,and an example is provided to answer the following questions：（1） Is every 1-sequentially quotient map sequence-covering？（2）Is every open map of a sequential space 1-sequence-covering？（3）Does not every LSC set-valued map from zero-dimensional paracompct spaces to a Lasnev space have continuous selection？