“抗震救灾,众志成城”,2008年5月15日成都军区向汶川等灾区空投包括5万份干

题型:计算题

问题:

“抗震救灾,众志成城”,2008年5月15日成都军区向汶川等灾区空投包括5万份干粮、2.5万双军用胶鞋、0.5万床棉被在内的救灾物资.直升飞机沿水平方向匀速飞往救灾物资集结地.图示为悬挂着m=500kg空箱的悬索与竖直方向的夹角θ1=45º;而直升机载上救灾物资飞往灾区时,加速度沿水平方向,大小稳定在a=1.5m/s2,悬索与竖直方向的夹角θ2=14º.若空气阻力大小不变,且忽略悬索的质量.(重力加速度g=10m/s2,tan14 º=0.25)       

试求:

小题1:空气阻力的大小;

小题2:箱中救灾物资的质量.

考点:受力分析
题型:计算题

患者,女性,32岁,有胃溃疡病史5年,近日出现上腹胀痛,伴呕吐,常为隔夜食物,吐后腹痛可缓解,此时重要的措施为()

A.迅速建立静脉通道

B.镇静、止吐

C.解痉止痛

D.禁食洗胃

E.密切观察病情变化

题型:计算题

(二)

Artificial flowers are used for scientific as well as for decorative purposes. They are made from a variety of materials, such as wax and glass, so skillfully that they can scarcely be distinguished from natural flowers. In making such models, painstaking and artistry are called for, as well as thorough knowledge of plant structure. The collection of glass flowers in the Botanical Museum of Harvard University is the most famous in North America and is widely known throughout the scientific world. In all, there are several thousand models in colored glass, the work of two artist-naturalists, Leopold Blaschka and his son Rudolph.

The intention was to have the collection represent at least one member of each flower family native to the United States. Although it was never completed. It contains more than seven hundred species representing 164 families of flowering plants, a group of fruits showing the effect of fungus diseases, and thousands of flower parts and magnified details. Every detail of these is accurately reproduced in color and structure. The models are kept in locked cases as they are too valuable and fragile for classroom use.

Which of the following is NOT included in the display at the Botanical Museum of Harvard University()

A.Models of 164 families of flowering plants.

B.Magnified details of flower parts.

C.Several species of native birds.

D.A group of diseased fruits.

题型:计算题

()夹紧机构的增力比最大,自锁性最好。

A.斜楔

B.螺旋

C.偏心

D.铰链

题型:计算题

S8500支持下列哪些ACL()

A.基于数字标识的基本ACL

B.基于名字标识的基本ACL

C.基于数字标识的高级ACL

D.基于名字标识的高级ACL

题型:计算题

威尔逊认为,住各种社会监督中,居于核心地位,具有最高权威的是( )

A.立法监督

B.司法监督

C.公共舆论监督

D.政党监督

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