下列排列顺序正确的是 [ ] A.常温下将0.1 mol·L-1 NH4Cl

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问题:

下列排列顺序正确的是 

[     ]

A.常温下将0.1 mol·L-1 NH4Cl溶液与0.05 mol·L-1 NaOH溶液等体积混合,c (Cl-)> c (Na+)> c(NH4+)> c (OH-)> c (H+)

B.常温下物质的量浓度相等的①NH4HSO4②CH3COONH4③NH4Cl三种溶液中c(NH4+):①>③>②

C.0.1mol·L-1的NaHA溶液,其pH=11,则溶液中:c(HA-)>c(OH-)>c(A2-)>c(H2A)

D.在相同条件下,将足量AgCl加入等体积的①0.01 mol·L-1 KCl②0.1 mol·L-1 KCl溶液③蒸馏水三种液体中,所能溶解的AgCl质量关系为:①>②>③

考点:粒子浓度大小的比较
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When ______ the twins, you will find the differences between them.[ ]

A. compared

B. compare

C. comparing

D. compares

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近几十年来,水资源不足已成为许多国家经济发展的严重阻碍,甚至危及国家的安全和民族的生存,读图回答:

(1)世界上最缺水的国家中,绝大部分地区的气候特点是          ,其原因主要是                    。全世界有许多地区因水而引发冲突,其中最典型的是        地区。

(2)世界上唯一的城市岛国是   (填图上数字代号),该国位于         气候类型区,它也被列为最缺水国家之一的原因是                        

(3)上海所处的地理纬度虽然与许多最缺水国家相近,但从水资源数量而言,上海并不缺水,这主要是由于上海地区受          环流的影响,然而现在上海却成为        性缺水城市。解决上海的水资源问题目前可以采取的措施有( )

A海水淡化                      B防治水体污染,改善长江、太湖来水的水质

C节约用水,减少浪费            D大力开采地下水

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Most parents of kids under age 8 don't worry about how much time they spend watching TV or using other media, from computers to smart phones to tablets PCs, according to a new survey that found a child's use of media often reflects how much time parents spend in the similar way.

¨We generally found that media use is not a source of conflict in the home" for families with young children, Ellen Wartella, a researcher from Northwestem University, told USA Today. She led a survey of 2,326 parents who have children 8 and younger.It found that in 80 percent of families, children's media use was not a problem, with 55 percent “not too" or“ not at all"  concerned about it. It also showed parents have more positive than negative feelings about how media consumption affects a child's learning and the development of creativity.The exception is video games, which are viewed more negatively than TV, computers or mobile devices.“Parents rated video games as more likely to have a negative effect on children's school performance, attention time, creativity, social skills, behavior and sleep than any other medium," the researchers said in a news conference about the survey.

¨The findings exposes a generational shift (转移) in parental attitudes about technology's role in young children's lives," said Wartella.“Today's parents grew up with technology as a central pact of their lives, so they think about it differently than earlier generations of parents, instead of a battle with kids on one side and parents on the other, the use of media and technology has become a family affair. "

The researchers identified three media environments created by parents: media-centric (39 percent of families) , media-moderate (45%)and media-light (16%). Children  in media-centric families spend at least three hours more each day watching TV or using computers, video games and tablet PCs don't make parenting easier.And 88 percent of parents say they are most likely to turn to toys or activities to keep their children occupied.Slightly fewer turn to books (79%) and TV(78%).

The survey didn't look at how media affects children. That's a topic that the American Academy of Pediatrics has handled a number of times. The AAP says studies have found too much media use can lead to attention- problems, school difficulties, sleep and eating disorders and being fat. In addition, the Internet and cell phones can provide platforms for illegal and risky behaviors.¨By limiting screen time and offering educational media and non-electronic formats (格式)such as books, newspapers and board games, and watching television with their children, parents can help guide their children's media experience. Putting questionable content into context and teaching kids a700ut advertising contributes to their media literacy (素养) ," it says.

The pediatricians' group says parents should have “screen-free zones"  and TV should be turned off during dinner. At most, it recommends children and teens engage with entertainment media for no more than two hours a day and that should be high-quality content. It is important for kids to spend time on outdoor play, reading, hobbies  and  using their imaginations  in free  play.“ Kids  under 2 should not use television and other entertainment media because their brains are developing quickly and they learn best from direct human interaction," the group says.

An article on screen time by t.he Mayo Clinic also notes problems linked t.o over screen time, including  being  fat, irregular  sleep , behavioral  problems , weak  school  performance , violence  and  less time for active and creative play.

小题1:Parents have more negative than positive feelings about media consumption like    

A.computers

B.smart phones

C.video games

D.tablets PCs小题2:Most parents don't worry about kid's media use because        

A.they can limit the screen time

B.they want their children happy

C.they also grew up with technology

D.they can teach their children themselves小题3:From the data of the survey, we learn       

A.children in media-centric families are smarter than others

B.children in media-light families spend one hour watching TV

C.more than half of the parents think children's media use was a problem

D.media-centric children spend more than three hours each day on media use小题4:To make parenting easier, most parents probably        

A.try to persuade their children to read books

B.ask their children questions while watching TV

C.allow their children watching TV or using computers

D.turn to toys or activities to keep their children occupied小题5:Which of the following is a suggestion by the researchers?

A.Media use time for babies under 2 should be limited.

B.Entertainment media use should be high-quality content.

C.Schools should provide more time for active and creative play.

D.Home media use should provide platforms for illegal and risky behaviors.

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什么事情能够拯救罪恶和错误?

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汽车槽车自流卸车系统由()卸车软管、卸油管路及控制阀门构成。

A、高架油罐

B、低位罐

C、油罐

D、卧罐

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