在花瓣中，有一种叫“花青素”的色素，当它遇到酸性物质时会变成（） A.黄色 B.红色

During the 1980s, unemployment (失业人数) and underemployment (不充分就业) in some countries was so high as 90 per cent. Some countries did not 【B1】 enough food; basic needs in housing and clothing were not 【B2】 . Many of these countries looked 【B3】 the industrial processes of the developed nations for solution. 【B4】 , problems cannot always be solved by 【B5】 the industrialized nations. Industry in the developed nations is highly automated and very 【B6】 . It provides fewer jobs than labor-intensive industrial 【B7】 , and highly skilled workers are needed to 【B8】 and repair the equipment. These workers must be trained, 【B9】 many nations do not have the necessary training institutions. Thus, the 【B10】 of importing industry becomes higher. Students must be sent abroad to receive vocational and 【B11】 training. 【B12】 , just to begin training, the students must 【B13】 learn English, French, Germans, or Japanese. The students then spend many years abroad, and 【B14】 do not return home. All nations agree that science and technology should be shared. The point is: countries 【B15】 the industrial processes of the developed nations need to look carefully 【B16】 the costs, be cause ninny of these costs are 【B17】 Students from these nations should 【B18】 the problems of the industrialized countries closely. 【B19】 care, they will take home not the problems of science and technology, 【B20】 the benefits.

A．tackle

B．learn

C．study

D．realize

设等差数列{a_n}的前n项和为S_n，若S₃=12，则a₂=（　　）

A．3

B．4

C．5

D．6

某甲在抢劫时造成被害人重伤，法院以抢劫罪判处某甲有期徒刑15年，并处罚金5万元，赔偿被害人经济损失5万元。经查，某甲个人财产只有8万元，对本判决的财产部分应当如何执行( )

A．罚金和赔偿经济损失以某甲现有财产按同等比例同时执行

B．先执行罚金5万元，剩余的3万元赔偿给被害人

C．先执行赔偿经济损失5万元，剩余的3万元作为罚金执行

D．先执行罚金5万元，经济赔偿不足部分，待甲刑满后继续履行赔偿义务

位置公差包括直线度.平面度.椭圆度.圆柱度.线轮廓度和面轮廓度。

目前，我国基金管理公司自批准筹建之日起（）个月内必须开业。

A．6 

B．9 

C．12 

D．18