问题 单项选择题

硬膜外血肿是()

A.右侧内囊前支卵圆形高密度造影

B.环池内高密度影

C.右眶额回斑片状高密度,周边伴水肿

D.左侧颞部颅板下梭形高密度

E.左侧额部颅板下新月形水样密度

答案

参考答案:D

单项选择题

某数据库中有员工关系E、产品关系P、仓库关系W 和库存关系I,其中:员工关系E(employeeID, name, department)中的属性为:员工编号,姓名,部门;产品关系P(productID,name, model, size, color)中的属性为:产品编号,产品名称,型号,尺寸,颜色;仓库关系W(warehouseID, name, address, employeeID)中的属性为:仓库编号,仓库名称,地址,负责人编号;库存关系I(warehouseID, productID, quantity)中的属性为仓库编号,产品编号和产品数量。 a. 若要求仓库关系的负责人引用员工关系的员工编号,员工关系E 的员工编号、仓库关系W 的仓库编号和产品关系P 的产品编号不能为空且惟一标识一个记录,并且仓库的地址不能为空,则依次要满足的完整性约束是 (48) 。 b. 若需得到每种产品的名称和该产品的总库存量,则对应的查询语句为: SELELCT name, SUM(quantity) FROM P, I WHERE (49) c. 若需得到在所有仓库中都存在的产品的名称,则对应的查询语句为: SELECT name FROM P WHERE (50) (SELECT * FROM W WHERE NOT EXISTS (SELECT * FROM I WHERE P.productID=I.productID AND W.warehouseID=I.warehouseID))

(48)处填()。

A.实体完整性、参照完整性、用户定义完整性

B.参照完整性、实体完整性、用户定义完整性

C.用户定义完整性、实体完整性、参照完整性

D.实体完整性、用户定义完整性、参照完整性

单项选择题

Many in the Middle East have difficulty in adjusting themselves to the new situation created by the departure of the imperial powers. For the first time in almost 200 years, the rulers and people of the Middle East have to accept the final responsibility for their own affairs, to make their own mistakes and to accept the consequences. This is difficult to internalize, even to perceive, after so long a period. For the entire lifetimes of those who formulate and conduct policy at the present time and of their predecessors for many generations, vital decisions were made elsewhere, ultimate control lay elsewhere, and the principal task of statesmanship and diplomacy was as far as possible to avoid or reduce the dangers of this situation and to exploit such opportunities as it might from time to time offer. It is very difficult to forsake the habits not just of a lifetime but of a whole era of history. The difficulty is much greater when alien cultural, social and economic preeminence continues and even increases, despite the ending of alien political and military domination.

Military and to a growing extent political intervention by the West has indeed ended, but the impact of its science and culture, its technology, amenities and institutions remains and even increases. As in other parts of the non-Western world, this impact has been and will be enormous. In these circumstances, it is natural that Middle Easterners should continue to assume—and proceed on the assumption—that real responsibility and decision still lie elsewhere. In its crudest form, this belief leads to wild and strange conspiracy theories directed against those whom they regard as their enemies—Israel, and more generally the Jews, the United States, and more generally the West. No theory is too absurd to be asserted or too preposterous to be widely and instantly believed. Even among more responsible statesmen and analysts, a similar belief in alien power, albeit in a less crude form, often seems to guide both analysis and policy. Some even go so far as to invite outside intervention, presumable in the belief that only outside powers have the capacity to make and enforce decisions. A case in point is the constant appeal to the United States to involve itself in the Arab Israel conflict, oddly coupled with the repeated accusation of "American imperialism. "

This state of mind is likely to continue for some time, with appeals for support or even intervention to the United States, to Russia and even to the European Union. In time, no doubt, Middle Eastern governments and people will learn how to use this window of opportunity to the best advantage—that is, of course, if the window remains open long enough.

The fact that the Middle Eastern countries often rely on the United States in resolving their conflicts shows that they believe that()

A. American imperialists still have control over the world affairs

B. outside powers are more capable of effective decisions

C. they are weaker than Israel and cannot defeat it

D. Israel is assisted and manipulated by the United States