Task: Text Matching
Input (English): Sentence1: I have been tested for every STD everything came back normal the only problem is my pH is at 8 how do I lower to 4? 
 Sentence2: Hello doctor I have issues with vaginal PH but is better now? My doctor said me it may be because of STD's or yeast infections. May I ask what are the common causes of PH changes as I have been tested  negative for both STD's and yeast infections. 
Output (English): Dissimilar