在按层次遍历二叉树的算法中，需要借助的辅助数据结构是( )。A．有序表 B．线性表

引起夜盲的疾病有（）

A.囊样黄斑水肿

B.脉络膜缺损

C.视网膜色素变性

D.视 * * 水肿

E.虹膜睫状体炎

在多元文化并存的移民城市，如何使以上海方言为载体的沪语文化作品保持恒久魅力？若以主要矛盾和次要矛盾辩证关系思考，关键是

A．政府出台相关政策，扶持沪语文艺作品的创作活动

B．增强沪语文艺作品文化底蕴，彰显其独特艺术生命力

C．借鉴其他艺术表现形式，扩大欣赏沪语文艺作品的群体

D．借助媒体的宣传推广，营造良好的沪语文艺作品文化环境

下列选项中，属于物料平衡中化学元素平衡的是（）。

A、氢平衡

B、硫平衡

C、重金属平衡

D、氮平衡

淡彩效果婚妙照的用光（）。

A、可由顾客任意选择

B、要用软光，柔光箱的规格要大些

C、要用硬光，柔光箱的规格越小越好

D、既可以用硬光，选择规格小些的柔光箱，也可以由摄影师任意选择

American Museum of Natural History is one of the largest natural and historic museums in the world and one of the main natural history research and education centres in the United States, set up in 1869 and located in the west of the Central Park, Manhattan District, New York. It (1) 7 hectares in its total area, (2) classical types of buildings. The (3) of ancient creatures and humanity is (4) the first place of all the museums in the world, (5) the representative samples from South America, Africa, Europe, Asia and Australia were collected, besides those from the (6) country, the United States.

In the museum, there are five kinds of exhibits, including astronomy, mineralogy, human history, and animals in the (7) times and those in modern times. There are thirty-eight exhibition halls with different (8) from 500 to 1,500 square metres. Besides these, there is a Roosevelt Memorial Hall in (9) of President Roosevelt who supported the (10) of the museum, which is also used to have a special exhibition, showing the new important (11) on natural sciences and (12) affairs and social problems, and special topics connected closely with the life of the citizens. Besides this, it is also used for avocation (13) to have all kinds of scientific activities in the laboratories, centres of natural science and centres for citizens. There are more than 10 (14) research departments mainly (15) for collection of samples, research and work of publication.

In the museum, there are (16) and sub-libraries of Aulspond ancient amniote, with about 300 thousand books and magazines (17) natural history, many of (18) are very valuable monographs for the first edition. It has published many expert books and magazines, and a large number of propaganda materials, (19) which are the two magazines, Natural History and Members of Museum that have the biggest (20) of their magazines.

10（）

A.cause

B.fate

C.property

D.fortune