Dental work is usually quite expensive. Appointments are usually
            made far in advance, but many dentists will try to fit you if you
            have an urgent problem.
            牙医行业通常索价高昂，而且看牙医一般都老早预约。 但是如果你有紧急情况，很多牙科医生还是会设法抽空给你看的。

            1.A: How long have you felt like this?
            B: It started bothering me yesterday afternoon.
            A: I think I'd better take an X-ray.
            B: Can you see anything?
            A: It's a small cavity. It should be easy to fill.

            2.A: When did your toothache start?
            B: It's been this way for a few days.
            A: Let me take a look at it.
            B: What do you think?
            A: You're got an abscess. I don't think we can save the tooth.

            3.A: How long has it hurt?
            B: The pain started last night.
            A: Well, let's have a look.
            B: What are you going to have to do?
            A: Your gums seem to be inflamed. You'll need treatment.

            4.A: How long have you been in pain?
            B: It started to hurt when I was eating dinner.
            A: Open your mouth as wide as you can, please.
            B: How bad is it?
            A: It's quite serious. I'm afraid we'll have to pull the tooth