题目内容：

We brush our teeth daily, but do you know everything you need to know about dental care and hygiene? Believe it or not, there is a lot more than most people realize. Luckily, here are several apps that can help you.

●Brush DJ

You should brush your teeth for full two minutes as recommended by dentists, but that time can be difficult to judge. Many recommend you listen to music, because many songs are just around two minutes in length. Brush DJ has loads of great tunes that will get you into the two­minute habit. There are both songs to listen to, and videos to watch, and you'll find a variety of awesome tunes.

●Orasphere

It's recommended that Orasphere videos be used by dentists for their patients, so they can learn about procedures. Those who do use these videos say that the software can greatly decrease the amount of time it takes to explain procedures to patients.

●American Dental Association(ADA)

Everything you ever wanted to know about your teeth, and then some, can be found on the American Dental Association(ADA) website. You'll find loads of great articles that have the latest news about dentistry（牙科）. Those interested in dental careers will find plenty of information to head them in the right direction, and there's even a section devoted to public dental programs, including Give Kids a Smile and Fluoride in Water.

●DDS GP

Here is more presentation software that explains all types of dental procedures. This is helpful for dentists to have, because they can better explain procedures to their patients.

●Dentistry IQ

You can find information for dentists, hygienists, assistants, office managers, and more at Dentistry IQ. You can also get information about new products, clinical practices, and much more. In addition, you can learn about career opportunities, the most recent practices, and a whole lot more.

1.What is the dentists' suggestion about brushing teeth?

A. Trying to brush as long as possible.

B. Listening to music while brushing.

C. Spending two minutes in brushing.

D. Brushing your teeth before breakfast.

2.Why are dentists recommended to use Orasphere videos?

A. To learn about procedures to shorten their explanation time.

B. To explain all types of dental procedures to their patients.

C. To listen to some music around two minutes in length.

D. To get plenty of information in the right direction.

3.How can the users benefit from American Dental Association(ADA)?

A. By getting free videos about oral care.

B. By getting access to various activities.

C. By getting information about new products.

D. By getting updated news about dentistry.

4.Which one would you feel interested in if you want to be a dentist?

A. Brush DJ.    B. Dentistry IQ.

C. Orasphere.    D. DDS GP.