问题 选择题

下列反应中必须加入还原剂才能进行的是

A.Zn→Zn2

B.H2→H2O

C.CaO→Ca(OH)2

D.CuO→Cu

答案

答案:D

题目分析:应用还原剂失去电子,化合价升高,所以反应中必须加入还原剂才能进行,这说明选项中的微粒应该是得到电子,化合价降低作氧化剂,据此可知A、锌的化合价升高,需要加入氧化剂;B、氢元素的化合价升高,需要加入氧化剂;C、元素的化合价均不变,所以不需要氧化剂;D、铜元素的化合价降低,需要加入还原剂,答案选D。

填空题
单项选择题

(B)

People from East Asia tend to have more difficulty than those from Europe in distinguishing facial expressions-and a new report published online in Current Biology explains why.

Rachael Jack, University of Glasgow researcher, said that rather than scanning evenly across a face as Westerners do, Easterners fix their attention on the eyes.

"We show that Easterners and Westerners look at different face features to read facial expressions," Jack said, "Westerners look at the eyes and the mouth in equal measure, whereas Easterners favor the eyes and neglect the mouth."

According to Jack and her colleagues, the discovery shows that human communication of emotion is more complex than previously believed. As a result, facial expressions that had been considered universally recognizable cannot be used to reliably convey emotion in cross-cultural situations.

The researchers studied cultural differences in the recognition of facial expressions by recording the eye movements of 13 Western Caucasian and 13 East Asian people while they observed pictures of expressive faces and put them into categories: happy, sad, surprised, fearful, disgusted, angry, or neutral. They compared how accurately participants read those facial expressions using their particular eye movement strategies.

It turned out that Easterners focused much greater attention on the eyes and made significantly more errors than did Westerners. "The cultural difference in eye movements that they show is probably a reflection of cultural difference in facial expressions," Jack said. "Our data suggest that whereas Westerners use the whole face to convey emotion, Easterners use the eyes more and mouth less. "

In short, the data show that facial expressions are not universal signals of human emotion. From here on, examining how cultural factors have diversified these basic social skills will help our understanding of human emotion. Otherwise, when it comes to communicating emotions across cultures, Easterners and Westerners will find themselves lost in translation.

In comparison with Westerners, Easterners are likely to()。

A. do translation more successfully

B. study the mouth more frequently

C. examine the eyes more attentively

D. read facial expressions more correctly