1.Going from junior high school to senior high school is a really big challenge.
2.The first week was a little confusing.
3.First, I had to think very carefully about which courses I wanted to take.
4.My adviser recommended that I should sign up for advanced literature because I like English and I'm good at it.
5.The main purpose of the course is to help improve each student's reading ability.
[我的发现]
(1)句1中名词短语a really big challenge在句中作表语;
(2)句2中形容词短语a little confusing在句中作表语;
(3)句3中副词短语very carefully在句中作状语;
(4)句4中名词短语advanced literature在句中作宾语;
(5)句5中名词短语the main purpose of the course在句中作主语。