具有n个结点的完全二叉树，其深度为 [1] 。

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．still

B．so

C．and

D．yet

某公司申请发行股票，保荐人为股票发行的主承销商，申请获得了国务院证券监督管理机构的核准，已经发行了但在上市申请中发现该公司尚不符合发行股票的条件，需要撤销发行核准决定，则下列关于证券持有人利益的保护机制说法正确的是()。

A．该公司应当按照市场价加算银行同期存款利息返还股票持有人

B．该公司仅就股票的发行价为限向股票持有人返还

C．主承销商应当与该公司承担连带责任

D．该公司的实际控制人可能与公司承担连带责任

从安全角度考虑，起重机设计时不须满足的条件是( )。

A．金属结构和机械零部件应具有足够的强度、刚性和抗弯曲能力

B．整机必须具有必要的抗倾覆稳定性

C．原动机具有满足作业性能要求的功率、制动装置提供必须的制动力矩

D．连续调整额定起重量

会场的大小应根据会议的规模而定，一般以每人平均______平方米为宜。

A．1～1.5
B．1.5～2
C．2～2.5
D．2～3

枪械通常包括（）、（）、（）、机枪和特种枪（霰弹枪、防暴枪、救生枪、信号枪）等。