Present perfect continuous

According to my worksheets that given by my teacher and my own idea

Present Perfect Continuous Tense is similar to Present Perfect Tense
In normal conditions they are EXCHANGEABLE

Except when you need to classify whether you are emphasizing the process or the result of the things that you are talking

For an example:

I have read that book and I'm now going to read another.
(To emphasize that i've finished the book)
I have been reading that book since nine o'clock.
(To emphasize that it takes some time/long time to finish that book.)

Your example:
I have been thinking about what you said and I've decided to take your advice.
(1st sentence(Using P.P.C.tense):To emphasize the process of thinking about what "you" said.
2nd sentence(Using P.P.tense:To emphasize that taking "your" advice.)

I have thought about what you said and I decide to take your advice.
(To emphasize that I did think about what "you" said;means that i did do that)

Honestly,you'll probably get correct answers if you use Present Perfect Tense if you really confused by them:D

Well i think you can figure out why it is 'Liz is away on holiday.' 'Is she? Where has she gone?' yoursely,don't you?

I have been thinking 可以解作我正在考慮

Where has she gone? 布她到了那裡，這已有離去未反的含意，無需要用 present perfect continuous tense.

Present perfect continuous tense implies a repetitive action that has just been done;and still goes on;up to a certain time in the past:-
eg:-have been thinking about(---)'ve decided=present perfect continous+present perfect(implies a waste of brain energy.)
eg:-have thought about (---) decides=present perfect tense+Simple Present Tense
=have read about (Hamlet),
=have just read about(Hamlet),
=have once read about(Hamlet).
----They all mean action just concluded when result state still present;continuing to present .
Have been studing Literature since morning...(a conc. of energy).
Have been reading about "Hamlet"...(In a Reported Speech usage on Eng.Lit.)You've just shifted VerbsTense Perfect Continuous towards Perfect;Now you've shifted verbsTense Perfect towards Perfect Continuous in:-has she gone----has she been going.

Using present perfect continuous tense usually implies a repetitive action which has just been done or still goes on.