请根据右图的溶解度曲线图,判断下列说法正确的是() A.a、b两物质的溶解度相

题型:选择题

问题:

请根据右图的溶解度曲线图,判断下列说法正确的是( )

A.a、b两物质的溶解度相等

B.t1℃时,向20g a固体加入50g 水,充分搅拌后固体能全部溶解

C.将t2℃时a、b饱和溶液降温到t1℃时,两者的溶质质量分数相等

D.b中含有少量a,可以用冷却热饱和溶液的方法提纯b

考点:固体溶解度气体溶解度
题型:选择题

雌孕激素对下丘脑及腺垂体的反馈,正确的是

A.雌激素——负反馈,孕激素——正反馈

B.雌激素——正反馈,孕激素——负反馈

C.雌激素——负反馈,孕激素——负反馈

D.雌激素——正、负反馈,孕激素——负反馈

E.雌激素——正、负反馈,孕激素——正反馈

题型:选择题

前列腺增生最主要的症状是

A.尿频

B.排尿困难

C.尿潴留

D.尿失禁

E.无痛性血尿

题型:选择题

Enter the information age. Information is the raw material for many of the business activities shaping this new era, (1) iron and steel were the basic commodities in the dawning of the industrial age.

The world’ s knowledge is said to be doubling (2) eight years. This knowledge explosion is (3) economic progress. The need to collect, analyze, and communicate (4) quantities of information is Spawning new products and services, creating jobs, and widening career opportunities.

The information age is (5) considered to be a phenomenon of the service sector of the economy, (6) a product of heavy industry. Certainly, burgeoning information technologies are creating new capabilities (7) knowledge-based service spheres. But changes just as dramatic are (8) industry, giving people the opportunity to do challenging work in exciting new ways.

Manufacturing is a full participant in the information age. From design (9) production, the manufacturing process has long been in formation-intensive. It always has required exacting communication to describe (10) goes into products and how to make them, Now, computer technology is giving factory managers new capability to gather all of this information and (11) it to control production.

Telecommunications are producing error-free communication between the design office (12) the factory, computer-aided design is enabling engineers to evaluate product performance and manufacturing process (13) video displays, before resources are committed to build and test prototypes. Techniques like these are bringing (14) new advances in manufacturing productivity.

Just as coal fueled the transformation to an industrial society, (15) microelectronics is powering the rise of the information age. Microelectronic information-management tools are strengthening U. S. industrial capability, (16) remains vital to America’ s economic well being and national security.

More and more manufacturing companies are (17) that the wise of information can give them a competitive edge. As companies emphasize (18) information management, talented people will continue to find (19) to make factories and milks sing with increased productivity.

In manufacturing as well as in services, information technology is a tool to (20) human creativity into productivity.

Read the following text. Choose the best word(s) for each numbered blank and mark A, B, C or D on ANSWER SHEET 1. (10 points)6()

A.in

B.by

C.over

D.on

题型:选择题

邓 * * 指出:“一个党、一个国家、一个民族,如果一切从本本出发,思想僵化,迷信盛行,那它就不能前进,它的生机就停止了,就要亡党亡国。”这段话,非常深刻地阐明了( )。

A.反对教条主义的重要性
B.改革开放的重要性
C.破除封建迷信的重要性
D.解放思想的重要性

题型:选择题

与碳钢相比,不锈钢冷作硬化现象严重,应在每次压延后进行()处理,恢复塑性。

A、正火

B、回火

C、淬火

D、退火

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