下列函数中是有界函数的是()。A、y=xsinxB、y=2x2C、y=cos2D、y

题型:单项选择题

问题:

下列函数中是有界函数的是()。

A、y=xsinx

B、y=2x2

C、y=cos2

D、y=√x

考点:数学高等数学高等数学题库
题型:单项选择题

热痉挛患者的突出表现是()

A.腓肠肌痉挛、疼痛

B.全身四肢无力

C.呼吸肌痉挛,呼吸麻痹

D.胸大肌痉挛,胸痛

E.肠道平滑肌痉挛,急腹痛

题型:单项选择题

有一毛石混凝土重力式挡土墙,如图3-18所示。墙高为5.5m,墙顶宽度为1.2m,墙底宽度为2.7m。墙后填土表面水平并与墙齐高,填土的干密度为1.90t/m。墙背粗糙,排水良好,土对墙背的摩擦角为δ=10°,已知主动土压力系数Ka=0.2,挡土墙埋置深度为0.5m,土对挡土墙基底的摩擦系数μ=0.45。

假定填土表面有连续均布荷载q=20kPa作用,试问,由均布荷载作用的主动土压力Eaq(kN/m),与下列何项数值最为接近()?

A.24.2

B.39.6

C.79.2

D.120.0

题型:单项选择题


阅读下列关于系统级测试的叙述,回答问题1至问题3。
[说明]
在信息系统工程监理中,系统级的测试评估相当重要,系统级测试可分为平台建设质量保证测试、信息系统质量保证测试和信息系统工程安全评估三大部分。

[问题3]
信息系统工程安全应包括哪些方面的评估

题型:单项选择题

Shopping habits in the United States have changed greatly in the last quarter of the 20th century. (1) in the 1900s most American towns and cities had a Main Street. Main Street was always in the heart of a town. This street was (2) on both sides with many (3) businesses. Here, shoppers walked into stores to look at all sorts of merchandise: clothing, furniture, hardware, groceries. (4),some shops offered (5) .These shops included drugstores, restaurants, shoe-repair stores, and barber or hairdressing shops. (6) in the 1950s, a change began to (7) .Too many automobiles had crowded into Main Street (8) too few parking places were (9) shoppers. Because the streets were crowded, merchants began to look with interest at the open spaces (10) the city limits. Open space is what their car-driving customers needed. And open space is what they got (11) the first shopping centre was built. Shopping centres, or rather malls, (12) as a collection of small new stores (13) crowded city centres. 14 by hundreds of free parking space, customers were drawn away from (14) areas to outlying malls. And the growing (16) of shopping centres led (17) to the building of bigger and betterstocked stores. (18) the late 1970s,many shopping malls had almost developed into small cities themselves. In addition to providing the (19) of one stop shopping, malls were transformed into landscaped parks, (20)benches, fountains, and outdoor entertainment.

请在12处填上正确答案()

A.started

B.founded

C.set up

D.organized

题型:单项选择题

继电保护设备处于异常状态是指单项特征状态量或总体评价结果变化较大,已接近或略微超过标准限值,应监视运行,采取相应的处理措施,必需马上安排停电定检。()

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