在访问数据库时,为建立实际的网络连接,把URL、数据库用户名和密码传给Driver-

题型:单项选择题

问题:

在访问数据库时,为建立实际的网络连接,把URL、数据库用户名和密码传给Driver- Manager的方法是( )

A.getconnection()

B.getConnection()

C.Connection()

D.connection()

考点:计算机等级考试JAVA二级JAVA笔试
题型:单项选择题

人类在使用金属的历史进程中,经历了铜、铁、铝之后,第四种将被广泛应用的金属被科学家预测是钛(Ti),它被誉为“未来世纪的金属”.试回答下列问题: 

(1)Ti元素在元素周期表中的位置是第________周期第________族;其基态原子的价电子排布为________.

(2)在Ti的化合物中,可以呈现+2、+3、+4三种化合价,其中以+4价的Ti最为稳定.

①偏钛酸钡的热稳定性好,介电常数高,在小型变压器、话筒和扩音器中都有应用.偏钛酸钡晶体中晶胞的结构示意图如图所示,它的化学式是________.

②已知Ti3+可形成配位数为6的配合物.现有含钛的两种颜色的晶体,一种为紫色,另一种为绿色,但相关实验证明,两种晶体的组成皆为TiCl3·6H2O.为测定这两种晶体的化学式,设计了如下实验:

a.分别取等质量的两种配合物晶体的样品配成待测溶液;

b.分别往待测溶液中滴入AgNO3溶液,均产生白色沉淀;

c.沉淀完全后分别过滤得两份沉淀,经洗涤干燥后称量,发现原绿色晶体的水溶液与AgNO3溶液反应得到的白色沉淀质量为紫色晶体的水溶液与AgNO3溶液反应得到的沉淀质量的2/3. 则绿色晶体配合物的化学式为____________________,绿色晶体中含有的化学键类型是________.

题型:单项选择题

按库仑公式计算挡土墙上的地震主动土压力时,下述不正确的是()。

A.墙背填土表面按水平考虑

B.公式中的容重γ用γ/cosθ代替

C.土的内摩擦角φ及墙背与土的摩擦角艿δs分别修正为φ-θ和δs+θ

D.地震角应根据基本烈度按浸水与非浸水两种情况查表求得

题型:单项选择题

下列哪项不属机械性损伤中外力作用方式()。

A.牵拉

B.压缩

C.剪切

D.折曲和扭转

E.应力

题型:单项选择题

举行集会、游行、示威,主管机关不许可的,将不许可决定书通知其负责人,无须说明理由。

题型:单项选择题

Man cannot go on increasing his number at the present rate. In the (56) 30 years man will face a period of crisis. (57) experts believe that there will be a widespread food (58) . Other experts think this is (59) pessimistic (悲观的), and that man can prevent things from (60) .

(61) thing that man can do is to limit the (62) of babies born. The need (63) this is obvious, but it is not (64) to achieve. People have to be (65) to limit their families. In the countries of the population (66) , many people like big families. The parents think that this (67) a bigger income for the family and ensures there will be someone in the family who will look (68) them in old age.

Several governments have (69) birth control policies in recent years. (70) them are Japan, China, India and Egypt. In some (71) the results have not been successful. Japan has been an (72) . The Japanese adopted a birth control policy in 1948. People were (73) to limit their families. The birth (74) fell from 34.3 per thousand per year to about 17.0 per year (75) present.

57()

A.Any

B.Some

C.More

D.All

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