在企业销售物流的效率评价指标中，经济效率指的是（）的比值。A.迅速及时完成销售物流量

男性45岁。诊断风湿性心脏病二尖瓣病5年。房颤半年，为纠正房颤来院。

若左心房内有异常回声下列哪项正确（）

A.复律前后应用华法林治疗各2周

B.复律前应用华法林治疗2周

C.复律后应用华法林治疗2周

D.复律前后用阿司匹林和潘生丁治疗2周

E.不需治疗

The girls in this sixth grade class in East Palo Alto, California, all have the same access to computers as boys. But researchers say, by the time they get to high school, they are victims of what the researchers call a major new gender (性别) gap in technology. Janice Weinman of the American Association of University Women says, "Girls tend to be less comfortable than boys with the computer. They use it more for word processing rather than for problem solving, rather than to discover new ways in which to understand information."

The research on girls and computers is ______.
A. based on a few recent articles B. presented by one person
C. based on thousands of studies D. not considered well grounded

After re-examining a thousand studies, the American Association of University Women researchers found that girls make up only a small percentage of students in computer science classes. Girls consistently rate themselves significantly lower than boys in their ability and confidence in using computers. And they use computers less often than boys outside the classroom.An instructor of a computer lab says he’s already noticed some differences. Charles Cheadle of Cesar Chavez School says, "Boys are not so afraid they might do something that will harm the computer, whereas girls are afraid they might break it somehow."
Six years ago, the software company Purple Moon noticed that girls’ computer usage was falling behind boys. Karen Gould says, "The number one reason girls told us they don’t like computer games is not that they’re too violent, or too competitive. Girls just said they’re incredibly boring."
Purple Moon says it found what girls want, characters they can relate to and story lines relative to what’s going on in their own lives. Karen Gould of Purple Moon Software says, "What we definitely found from girls is that there is no intrinsic (固有的) reason why they wouldn’t want to play on a computer; it was just a content thing."
The sponsor of the study says it all boils down to this: the technology gender gap that separates the girls from the boys must be closed if women are to compete effectively with men in the 21st century.

下述哪种情况肾小球滤过率将升高( )。

A．血压升至18.6KPa(140mmHg)时

B．血压降至10.6KPa(80mmHg)以下时

C．血压升至26.5KPa(200mmHg)时

D．入球小动脉收缩时

E．肾血流量减少时

起重机的主要技术参数有（）、起升高度、各机构工作速度和质量指标等。

A、型号

B、起升质量

C、幅度

D、起重力矩

E、自重

设f(x，y)为连续函数，且

，其中D：u²+v²≤a²(a＞0)，则f(x，y)=______．