The most suitable verb to complete the sentence is have been reading.
So the full sentence would be: I have been reading this book for 30 minutes now.
This is because "for 30 minutes now" indicates an action that started in the past and is still continuing in the present, which is best expressed by the present perfect continuous tense.
اذا كان لديك إجابة افضل او هناك خطأ في الإجابة علي سؤال I …… this book for 30 minutes now اترك تعليق فورآ.
