下列各组数中,相等的是( ) A.-1与(+2)+(-1) B.|-32|与-(-3

题型:选择题

问题:

下列各组数中,相等的是(  )
A.-1与(+2)+(-1)B.|-
3
2
|与-(-
3
2
C.-
32
4
与-
9
16
D.(-4)3与-12
考点:比较有理数的大小
题型:选择题

再生障碍性贫血的主要诊断依据是()

A.全血细胞减少

B.网织红细胞减少

C.造血原料减少

D.骨髓造血功能低下

E.一般抗贫血药物治疗无效

题型:选择题

下列关于新闻组服务的说法,错误的是( )。

A.目前,最大规模的网络新闻组是USENET,它的基本通信方式是电子邮件,基本组织单位是讨论组

B.网络新闻组是一种利用网络进行专题讨论的国际论坛

C.USENET服务器上存储的用户信息会周期性地转发给其他服务器

D.USENET采用点对点的通信方式

题型:选择题

     Most American kids love Halloween treats, but a bucket of Halloween candy can be a dentist's

nightmare. Some parents try to get rid of half of the candy after their children go to bed, but dentists

say parents also need to separate the good kinds of treats from the bad ones.

     It is not exactly what a child eats that truly matters, but how much time it stays in his mouth.

According to pediatric dentist Dr. Kaneta Lott, the most damaging stuff is something that is sticky or

very hard and thus stays in the mouth for a long time.This is because we all have bacteria in our mouths.

When we eat, the bacteria take our food as their food and produce an acid that destroys the surface

of the teeth, causing cavities to form. The longer the food stays in the mouth, the more likely cavities

will develop. Therefore, potato chips are worse than candy because they get stuck between teeth. For

the same reason, raisins and crackers are not the best choice. Hard candies take a long time to

consume and are also a bad choice for Halloween treats.

     If children really love candy, dentists recommend that they eat chocolate instead. Unlike hard

candies, chocolate dissolves quickly in the mouth.Besides, chocolate contains tannins, which help to

kill some of the bacteria in the mouth.But no matter what a child eats, brushing after each meal is still

the best way to fight cavities.

1. What is the main purpose of this passage?

A. To discuss how cavities can be treated.

B. To point out the problems with Halloween celebrations.

C. To tell parents what sweets are less damaging to their children’s teeth.

D. To teach parents the meaning of Halloween candy for their children.

2. Why are hard candies especially bad for teeth?

A. They may break the children’s teeth.

B. They contain too much sugar.

C. They help bacteria to produce tannins.

D. They stay in the mouth for a long time.

3. According to the passage, which of the following is a better choice for Halloween treats?

A. Chocolate.      

B. Crackers.

C. Raisins.  

D. Potato chips.

4. According to the passage, which of the following is true of tannins?

A. They are produced when the bacteria digest the food.

B. They help to get rid of some bacteria in the mouth.

C. They help chocolate to dissolve more quickly.

D. They destroy the surface of the teeth.

题型:选择题

YB25/YB45包装机显示“内衬纸异位”的原因之一是内衬纸张()。

A.未校直

B.未压花

C.缺拉片

D.未剔除

题型:选择题

景观结构格局

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