Answer: C: Is not reliable.
Explanation:
The test is not reliable if a depressed person took it and has Depression but <em>the non-depressed person got the same thing, But they are not depressed</em>.
The two sentences are:
1. It is easy to learn how to whistle.
2. Whistling a little tune is a great way to lift your spirits.
The speaker is saying good job
No, abbreviations are not necessary in the thesis.