下列属于辅助操纵系统的是:().A.方向舵 B.升降舵 C.前缘襟翼 D.副翼

题型:单项选择题

问题:

下列属于辅助操纵系统的是:().

A.方向舵

B.升降舵

C.前缘襟翼

D.副翼

考点:民航飞行签派员考试民航飞行签派员考试题库
题型:单项选择题

U.S. first lady Michelle Obama and her family have just ended their one-week trip in China. The whole world has paid attention to the two elegant and beautiful first ladies who have made a difference in the relationship(关系) between China and the U.S.A.

Mrs. Obama has visited the Forbidden City, the Great Wall, the Terracotta Warriors, and the pandas. She has tasted Peking Duck and experienced some other Chinese traditional culture. It is hoped that this trip to China can bring a real understanding of our eastern world to the first family of the United States.

Today, the number of exchange students between China and the U.S. has reached more than 4 million every year. There are more than 11,000 people traveling to and from each side of the Pacific(太平洋). If the two countries can increase the exchange in travel, language, cuisine, and cultural understanding, this will help a lot in improving the understanding between the two countries. 

Education was an important theme of Mrs. Obama’s visit, and it is crucial to the development of Sino-US relationship. China has an ancient tradition of placing a high value on education, and the first lady herself is an outstanding example of a person who changed her own destiny(命运) through education. She took education as the key theme of her speech at Peking University, encouraging students from the two countries to learn more about and get wider experience of each other.

小题1:The whole world has paid attention to the two wonderful ladies because ___________.

A. they are elegant and beautiful

B. they have made a difference in the relationship between China and the U.S.A.

C. they pay attention to education

D. they hope students can learn from each other

小题2:Mrs. Obama has visited the following places except___________.

A.Terracotta Warriors

B.the Forbidden City

C.the Great Wall

D.the Summer Palace小题3:The underline word “Sino” in the fourth paragraph probably means ______

A. China        B. Japan        C. Canada        D Australia

小题4:The theme of Mrs. Obama’s speech at Peking University is_________

A.understanding

B.education

C.Sino-US relationship

D.exchange students

题型:单项选择题

( )是保险人签发并附在保险单之后的批改保险单内容的凭证,其法律效力优于原保单的同类项目。

A.投保单

B.暂保单

C.批单

D.保险凭证

题型:单项选择题

[实验化学]

邻叔丁基对苯二酚(TBHQ) 是一种新颖的食品抗氧剂,其制备原理为:

实验过程中的主要步骤如下:

步骤1.向三口烧瓶中加入5.5g对苯二酚,5.OmL浓磷酸及20mL二甲苯(装置如图所示),启动搅拌器。

步骤2.缓缓加热到100-110°C,慢慢滴加7.5mL叔丁醇和5mL二甲苯组成的溶液,30-60min内滴完。

步骤3.升温到135-140°C,恒温回流2.5h。

步骤4.将反应液冷却到120°C,直到反应完成

步骤5.将反应液倒入烧杯,并用热水洗涤三口烧瓶,洗液并入烧杯中。

步骤6.冷却结晶,抽滤,回收滤液中的二甲苯和磷酸

步骤7.用二甲苯重结晶、脱色、冷水洗涤、干燥

(1)磷酸在实验中的作用是          

(2)本实验中二甲苯的作用是          

(3)步骤4中反应完成的标志是          

(4)步骤7脱色时,可用的脱色剂是          

(5)对合成得到的产品表征,还需要的主要现代分析仪器是                    

题型:单项选择题

下列关于以招标投标方式订立施工合同的说法中,正确的是( )。

A.提交投标文件是承诺

B.发放招标文件是要约

C.签订书面合同是承诺

D.发放中标通知书是承诺

题型:单项选择题

通常切丝机砂轮在刀片长度范围内做()往复移动磨刀。

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