In my opinion it is complete and correct, but there are some words wrong. Therefore, it must before it can be used to submit the job.
2. Answer
( 2.1) and serious about learning.
Edit is: serious about their learning.
(2.2) And the disadvantage.
Edit is: and a disadvantage.
(2.3) Concerns there.
Edit is: There are concerns.
3. Answer
In my opinion I think should use to get a data most out. First, should read to achieve accuracy in order to bring a use for in work. Then, the data analysis for bring use to do work. So, it’s very useful information source to work.