Acid, Alkaline and Neutral

Sarah : Do you remember what is Acid, Alkaline and Neutral?
Rina   : Of course! It is so easy!
Sarah : Are you sure?
Rina   : Yup!
Sarah :Okay, here's a question, name three subtances for Acid, Alkaline and Neutral.
Rina   : Um..Ahah! Acid is Lime, orange juice and shampoo. Alkaline is Rice and umm..
Sarah : See! You still didn't understand about Acid, Alkaline and Neutral!
Rina   : But I only can't remember the subtances only.
Sarah : The question will appear at the examination, you know that?
Rina   : Yeah! I almost forgot! But, what should I do? I still can't remember the subtances!
Sarah : Okay, le's go back to the question I asked. You said that the subtances of Acid is lime,     
           orange juice and shampoo. Shampoo is not Acid. It is Alkaline. And, you also said that
           Alkaline is rice. That is also wrong! Rice is Neutral.
Rina   : Oh! But, how do we know what is Acid, Alkaline and Neutral?
Sarah : Acid taste sour and change blue litmus paper to red. Alkaline taste bitter and change red
           litmus paper to blue. Neutral is tasteless. There is no colour changes at the litmus paper.
Rina   : Oh! Thanks for the tips! And now, I could remember it easily!
Sarah : You're welcome!