A: Can you tell me how this compares to that?
    　B: This one is much handier to carry.
    　--------------------------------------------------------------------------------
    　A: Which is the better material?
    　B: I'd say either is good.
    　--------------------------------------------------------------------------------
    　A: Why do you recommend this?
    　B: This is effective against a cold.
    　--------------------------------------------------------------------------------
    　A: What can this do that that can't?
    　B: This is portable but that isn't.
    　--------------------------------------------------------------------------------
    　A: What special features does this have?
    　B: this works without a battery, but that one needs one.
    　--------------------------------------------------------------------------------
    　A: Will I save money if I buy a dozen?
    　B: You can save about ten percent.
    　--------------------------------------------------------------------------------
    　A: What's the strong point?
    　B: One of the best things about it is that it is easy to operate.