下列哪项不是脑瘫发生的危险因素（） A.孕龄34～36周 B.低体重（ C.胎盘早剥

刘明用石灰石（杂质不与酸反应，也不溶于水）和稀盐酸反应制取二氧化碳，在准备将反应后的废液倒进废液缸时，发现实验桌上有一瓶未知质量分数的Na₂CO₃溶液，他决定利用该废液测定Na₂CO₃溶液中溶质的质量分数。他将废液过滤，然后向废液中慢慢滴加Na₂CO₃溶液，加入Na₂CO₃溶液的质量与生成沉淀质量的关系如右图所示。

（1）在加入Na₂CO₃溶液的过程中，开始时没有发现沉淀生成，说明滤液中的溶质除含有CaCl₂外，还含有______________；                    

（2）求Na₂CO₃溶液中溶质的质量分数。（计算结果精确到0.1%）

（3）求题（1）滤液中还含有溶质的质量（计算结果保留一位小数）。                   

The practice of students endlessly copying letters and sentences from a blackboard is a thing of the past. With the coming of new technologies like computers and smartphone, writing by hand has become something of nostalgic (怀旧的)skill. However, while today’s educators are using more and more technology in their teaching, many believe basic handwriting skills are still necessary for students to be successful---both in school and in life.

Virginia Berninger, professor of educational psychology at the University of Washington, says it’s important to continue teaching handwriting and help children acquire the skill of writing by hand.

Berninger and her colleagues conducted a study that looked at the ability of students to complete various writing tasks---both on a computer and by hand. The study, published in 2009, found that when writing with a pen and paper, participants wrote longer essays and more complete sentences and had a faster word production rate.

In a more recent study, Berninger looked at what role spelling plays in a student’s writing skills and found that how well children spell is tied to know well they can write. “Spelling makes some of the thinking parts of the brain active which helps us access our vocabulary, word meaning and concepts. It is allowing our written language to connect with ideas.” Berninger said.

Spelling helps students translate ideas into words in their mind first and then to transcribe(转换) “those words in the mind written symbols on paper or keyboard and screen,” the study said. Seeing the words in the “mind’s eye” helps children not only to turn their ideas into words, says Berninger, but also to spot(发现) spelling mistakes when they write the words down and to correct then over time.

“In our computer age, some people believe that we don’t have to teach spelling because we have spell checks,” she said. “But until a child has a functional spelling ability of about a fifth grade level, they won’t have the knowledge to choose the correct spelling among the options given by the computer.”

小题1:What makes writing by hand a thing of the past?

A．The absence of blackboard in classroom.

B．The use of new technologies in teaching.

C．The lack of practice in handwriting.

D．The popular use of smartphones.小题2:Berninger’s study published in 2009 ___________.

A．focused on the difference between writing by hand and on a computer.

B．indicated that students prefer to write with a pen and paper.

C．found that good essays are made up of long sentences.

D．discussed the importance of writing speed.小题3:Which of the following best shows the role of spelling?

A．Spelling improves one’s memory of words.

B．Spelling ability is closely related to writing ability.

C．Spelling benefits the translation from words into ideas.

D．Spelling slows down finding exact words to express ideas.小题4:What does “mind’s eye” in paragraph 5 mean?

A．Window.

B．Soul

C．Picture.

D．Imagination.小题5:What conclusion could be drawn from the passage?

A．Computers can help people with their choice of words.

B．Spell checks can take the place of spelling teaching.

C．Handwriting still has a place in today’s classrooms.

D．Functional spelling ability develops fast in the fifth grade.

用于侧向通过列车，速度超过50km／h的单开道岔，不得小于11号。

对于非结构化测试，影响面试信度的关键是（）

A、准确控制面试的进程

B、主考和评委的水平

C、公平、平等

D、面试试题合理

为了保证工装的良好技术状态，工装应进行定期检定修理。