下列哪项不是轮机员在值班期间的首要任务（）。A．保持机器安全运行 B．确保驾驶台命令

在哺乳动物细胞正向突变试验中，在受试物存在下，细胞对5-溴尿嘧啶脱氧核苷（BrdU）或三氟胸苷（TFT）等嘧啶类似物产生抗药性，说明（）

 

A.tk基因发生突变

B.hprt基因发生突变

C.gpt基因发生突变

D.Na⁺/K⁺ATPase基因发生突变

E.ras基因发生突变

某同学设计并制作了一种温度计，其结构如图所示，玻璃泡A内封有一定质量的气体，与A相连的细管B插在水银槽中，管内水银面的高度x即可反映泡内气体的温度，即环境温度，并可由B管上的刻度直接读出（B管的体积与A泡的体积相比可略去不计）．制作过程：将玻璃泡分别置于100℃与0℃的环境温度下，刻录下当时水银面的高度x，再以两次刻录下的刻度间距的

1

100

为最小刻度，将B管全部画上均匀刻度线，温度计便制作好了．

为检查该装置的可行性与准确性，该同学在某一恒定的大气压下提供不同的环境温度，通过对B管上的温度刻度与当时实际温度进行对比，以确定该温度计的可行性与准确性，测量获得的数据及B管上的温度刻度如下表所示：

实际温度t（℃）	-27	0	27	54	81	100
汞柱高x（cm）	25.8	20.4	15	9.6	4.2	0.4
温度刻度t（℃）	-31	-4	23	50	77	96

该同学根据表格中提供的信息，进行了以下分析：

（1）由表格中数据可得B管内汞柱高x的变化大小和实际温度T的变化大小的比值恒定，其比值大小为C=______cm/K；

（2）该同学认为上一结果说明该温度计制作时在B管上画上均匀刻度线的方法是正确的．试从理论及实际两方面分析并证明这一制作方法的正确性．

（3）由表格中数据推断此时实际的大气压强值p₀=______cmHg．

（4）虽然温度计原理上正确，但实际温度却与管上的刻度之间出现了明显偏差，该同学分析出现这一现象的原因可能是由于制作温度计时的大气压p₀′与此时实际的大气压p₀不同，p₀′比p₀______（填“偏大”或“偏小”）．说明这种温度计受环境大气压影响较大，为此该同学提出了修正方案，请写出修正后的实际温度表达式T_实=______（设已测量出的数据有温度测量值T_测、制作温度计时的大气压p₀′、测温时的大气压p₀）．

阅读理解。

     When the shooting of Harry Potter and the Deathly Hallows was complete, it was much more than a

movie wrap-up (结束).

     Rupert Grint, who played Ron Weasley, told The Sunday Times that he's happy to have the time for

romance now filming is over. Emma Watson, who is Hermione Granger in the movies, said she looked

forward to "finally being free, being my own person"-a change signaled (显示) by her new haircut.

     Daniel Radcliffe, who has been the face of the boy wizard since 2001, said that he "did cry like a little

girl" when the last movie finished.

     "It's like the ending of a relationship," he told The Vancouver Sun. "There's a sense of, 'God, what am

I going to do now?'" He said he was eager to see "what life holds for him beyond Hogwarts".

     Along with the three actors, Harry Potter fans, now in their late teens, came of age with J.K. Rowling's

characters. For them, the last film isn't just a goodbye to a decade (十年) of magic, but the close of their

childhoods.

     "We are the Harry Potter generation," Canadian Andrea Hill, 19, told The Vancouver Sun. "We started

in elementary school, reading about a boy our age who was going through the same things we were going

through. We grew up, so did he."

     For Emmy Chahal, an 18-year-old student, the series has been an inspiring journey. "That first book

was what sparked (激发) my love of literature (文学). It was the catalyst (催化剂) for everything-really

teaching me to appreciate my friends, and to face difficulties with a sense of courage (勇气)," she said.

"I have a sense of grief (伤心). The end of the movies is kind of the end of my childhood, too."

     Fortunately, to the delight of die-hard fans, there are many things that keep the boy wizard alive. For

example, in June this year, a Harry Potter theme park opened in Florida, US.

     Some schools in the US and UK also have Quidditch teams-players ride broomsticks (扫帚). "We're

not waiting anymore to see what happens to Harry next," Hill told The Vancouver Sun. She founded a

Quidditch club at Carleton University in Canada. "We're still engaged (投入) in that magical world."

1. How did Emma Watson feel when she finished the shooting of the Harry Potter series? [ ]

A. She cried like a little girl.

B. She was ready to move onto something new.

C. She was happy to have the time for romance.

D. She felt it was like the end of a relationship.

2. What did Daniel Radcliffe mean by saying he was eager to see "what life holds for him beyond Hogwarts"?[ ]

A. He was bored with life in Hogwarts.

B. He couldn't wait to graduate from Hogwarts.

C. He missed life in Hogwarts now he had left.

D. He was looking forward to new life out of Hogwarts.

3. The series has brought Emily Chahal all the following EXCEPT _____. [ ]

A. the chance to live in a magical world

B. the courage to face difficulties

C. the appreciation of her friends

D. encouragement to love literature

4. What is the main focus of the article? [ ]

A. Celebration of the close of childhood.

B. Fans' love for the Harry Potter series.

C. Mixed feelings about the end of the series.

D. Excited anticipation of the opening of the Harry Potter theme park.

提高吸收效率有哪些可行措施？

硅是钢的主要合金元素，主要是为（）而加入的。

A.提高塑性

B.提高韧性

C.脱氧去硫

D.改善冷脆性