and so on之后。

7.we→they　考查人称代词。此处指代students,所以要用they。

8.uses→use　考查主谓一致。use的主语是many students。

9.message→messages　考查名词的数。由下文得知发送信息给朋友和老师,应该用名词的复数形式。

10.singing→sung　考查非谓语动词。动词的过去分词作后置定语,逻辑主语songs被唱(sung)。

第二节 阅读理解

　　How fit are your teeth? Are you lazy about brushing them? Never fear: An inventor is on the case. An electric toothbrush senses how long and how well you brush, and it lets you track your performance on your phone.

　　The Kolibree toothbrush was exhibited at the International Consumer Electronics Show in Las Vegas this week. It senses how it is moved and can send the information to an Android phone or iPhone via a Bluetooth wireless connection.

　　The toothbrush will be able to teach you to brush right (don't forget the insides of the teeth!) and make sure you're brushing long enough. "It's kind of like having a dentist actually watch your brushing on a day-to-day basis," says Thomas Serval, the French inventor.

　　The toothbrush will also be able to talk to other applications on your phone, so developers could, for instance, create a game controlled by your toothbrush. You could score points for beating monsters among your teeth. "We try to make it smart but also fun," Several says.

　　Serval says he was inspired by his experience as a father. He would come home from work and ask his kids if they had brushed their teeth. They said "yes," but Serval would find their toothbrush heads dry. He decided he needed a brush that really told him how well his children brushed.

　　The company says the Kolibree will go on sale this summer, for $99 to $199, developing on features. The U.S. is the first target market.

　　Serval says that one day, it'll be possible to replace the brush on the handle with a brushing unit that also has a camera. The camera can even examine holes in your teeth while you brush.

1. Which is one of the feature of the Kolibree toothbrush?

　A. It can sense how users brush their teeth.

B. It can track users' school performance.