The paper can be divided into three parts: The first part is pre-Theory.
本论文主要内容可分为三个部分：第一部分主要为前期理论综述。
2
This is a key feature at least in theory as the Pre is seen as the biggest competitor to Apple's iPhone to date.
这是把Pre看成Apple的iPhone至今以来最大竞争对手的一个关键特性，至少从理论上来讲。
3
The researchers in New Zealand thought that their study would confirm this theory, so they specifically controlled for pre-existing mental health problems.