1. Which of these approaches is adopted depends on the concatenation of a number of factors. 这些方法中究竟采用哪一种，视若干相互联系的因素而定。
2. The concatenation cost function is a key factor affecting the naturalness of synthesized speech. 拼接代价函数是决定合成音自然度的重要因素之一。
3. The tree allows easy access to any of its nodes by means of a path, which is a concatenation of multiple keys. 这种树可以通过类似于路径的方式很方便地访问任一节点，这个路径由多个键值串接而成。
英英解释
n.
1. the state of being linked together as in a chain; union in a linked series
2. the linking together of a consecutive series of symbols or events or ideas etc
3. a series of things depending on each other as if linked together
4. the act of linking together as in a series or chain
