鲜或冷藏的莼菜

前运算阶段的思维特征主要有（　）。

A．以为外界的一切事物都是有生命的

B．一切以自我为中心

C．认知活动具有相对具体性

D．思维具有不可逆性

E．有了守恒观念

阅读理解

     What do you want to be when you grow up? A teacher? A doctor? How about an icecream taster?

      Yes, there really is a job where you can get paid to taste icecream.Just ask John Harrison, an

"Official  Taste Tester" for the past few years.Testing helps manufacturers to be sure of a product's

quality.During his career Harrison has been responsible for approving large quantities of the sweet

icecream-as well as for developing over 75 flavors.

      Some people think that it would be easy to do this job, after all, you just have to like icecream, right? No, there's more to the job than that, says Harrison, who has a degree in chemistry.He points out that a

dairy or foodscience degree would be very useful to someone wanting a career in this "cool" field.

     In a typical morning on the job, Harrison tastes and assesses 60 icecream samples.He lets the

icecream warm up to about 12?.Harrison explains, "You get more flavor from warmer icecream, which

is why some kids like to stir it, creating icecream soup."

     While the icecream warms up, Harrison looks over the samples and grades each one on its

appearance. "Tasting begins with the eyes, " he explains.He checks to see if the icecream is attractive and

asks himself, "Does the product have the color expected from that flavor?" Next it's time to taste!

Continuing to think up new ideas, try out new flavors, and test samples from so many kinds of icecream

each day keeps Harrison busy but happy-working at one "cool" job.

1. What is John Harrison's job?

A. An official.

B. An icecream taster.

C. A chemist.

D. An icecream manufacturer.

2. According to John Harrison, to be qualified in the "cool field",  it is helpful to ________.

A. keep a diary of work

B. have a degree in related subjects

C. have new ideas every day

D. find out new flavors each day

3. What does Harrison do first when testing icecream?

A. He stirs the icecream.

B. He examines the color of the icecream.

C. He tastes the flavor of the icecream.

D. He lets the icecream warm up.

4. What's the meaning of the underlined word "flavors" in Paragraph 2?

A. 味道  

B. 面包

C. 种类  

D. 品尝师

5. Which of the following is probably the best title of the passage?

A. Tasting with Eyes

B. Flavors of Icecream

C. John Harrison's Life

D. One Cool Job

行业集中度是衡量行业垄断程度的重要指标。

PLC包括（）。

A.中央控制单元

B.存储器和编程器

C.输入、输入电路

D.电源部分

箱内所有紧固螺丝都应有防松装置，以防松脱，在扣前箱大盖前对所有油管的连接螺母应用手锤敲打检查，以防漏紧。（）