停泵时应先关闭出料阀门,再停泵。

题型:判断题

问题:

停泵时应先关闭出料阀门,再停泵。

考点:选矿脱水工选矿脱水工(中级)选矿脱水工(中级)题库
题型:判断题

以下为12种中学化学中常见的物质:①Cu ②NaCl ③NaHSO4 ④SO3 ⑤H2SO4 ⑥C2H5OH ⑦CaCO3

⑧BaSO4 ⑨Cu(OH)2 ⑩Fe(OH)3 ⑩NaOH ⑩NH3·H2O

请按下列分类标准填空:

(1)属于电解质的是______(填序号,下同)。

(2)能电离出H+的是__________,属于酸的是__________。

(3)属于碱的是_________,其中属于难溶性碱的是__________。

(4)属于难溶性盐的是__________。

题型:判断题

级进模中,典型的定位结构有()和()等两种。

题型:判断题

以C18柱为固定相、乙腈-水为流动相进行HPLC分离()

A.分子量大的组分先出柱

B.分子量小的组分先出柱

C.极性强的组分先出柱

D.极性弱的组分先出柱

E.沸点高的组分先出柱

题型:判断题

人体安静状态下,哪种器官的动脉血和静脉血含氧量差值最大()

A.脑

B.肾脏

C.心脏

D.骨骼肌

E.肝脏

题型:判断题

Although there are many skillful Braille readers, thousands of other blind people find it difficult to learn that system. They are thereby shut (1) from the world of books and newspapers, having to (2) on friends to read aloud to them.

A young scientist named Raymond Kurzweil has now designed a computer which is a major (3) in providing aid to the (4) .His machine, Cyclops, has a camera that (5) any page, interprets the print into sounds, and then delivers them orally in a robot-like (6) through a speaker. By pressing the appropriate buttons (7) Cyclops’s keyboard, a blind person can "read" any (8) document in the English language.

This remarkable invention represents a tremendous (9) forward in the education of the handicapped. At present, Cyclops costs $ 50,000. (10) , Mr. Kurzweil and his associates are preparing a smaller (11) improved version that will sell (12) less than half that price. Within a few years, Kurzweil (13) the price range will be low enough for every school and library to (14) one. Michael Hingson, Director of the National Federation for the Blind, hopes that (15) will be able to buy home (16) of Cyclops for the price of a good television set.

Mr. Hingson’s organization purchased five machines and is now testing them in Maryland, Colorado, Iowa, California, and New York. Blind people have been (17) in those tests, making lots of (18) suggestions to the engineers who helped to produce Cyclops.

"This is the first time that blind people have ever done individual studies (19) a product was put on the market," Hingson said. "Most manufacturers believed that having the blind help the blind was like telling disabled people to teach other disabled people. In that (20) , the manufacturers have been the blind ones.

4()

A.paralyzed

B.uneducated

C.invisible

D.sightless

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