正与非门电路同时也是一个负或非门电路。

题型:判断题

问题:

正与非门电路同时也是一个负或非门电路。

考点:电气专工试题电气专工试题题库
题型:判断题

如图2所示,在水平地面上向右做直线运动的汽车,通过定滑轮用绳子吊起一物体,若汽车和被吊物体在同一时刻的速度为v1和v2,此时物体匀速上升,则下面说法正确的是(  )

A.汽车在做匀速直线运动,且v2=v1

B.汽车在做变加速直线运动,且v2>v1

C.汽车在做匀减速直线运动,且v2<v1

D.汽车在做变加速直线运动,且v2<v1

题型:判断题
不定项选择
二氧化碳对长波辐射有强烈的吸收作用,行星表面发出的长波辐射到大气以后被二氧化碳截获,最后使大气升温,大气中的二氧化碳像暖房的玻璃一样,只准太阳的辐射热进来,却不让室内的长波热辐射出去,大气中的二氧化碳的这种效应叫温室效应。这是目前科学界对地球气候变暖进行分析的一种观点,根据这种观点,以下说法成立的是(   )
A.在地球形成的早期,火山活动频繁,排出大量的二氧化碳,当时地球的气温很高

B.经过漫长的年代,地壳的岩石和气体二氧化碳发生化学反应,导致二氧化碳减少,地球上出现了生命

C.由于工业的发展和人类的活动,导致二氧化碳在空气中的含量增大,地球上的气温正在升高

D.现在地球正在变暖的原因是工业用电和生活用电的急剧增加,使电能和其他形式的能转化为内能

题型:判断题

Mike Maietta was eating lunch when he got a text message from his mom.

“Notre Dame,” it said. “Big envelope!”

Mike, a senior at a Californian high school, shouted with joy. The big envelope meant that the excellent university in Indiana had offered him a place in its Class of 2013. But the $51,300 annual fee is a big obstacle. So Mike and his parents are considering offers from several other colleges and are calculating the costs of tuition, housing and holiday trips home.

This year, money is the driving factor for a growing number of high school seniors, who have to decide what colleges to attend this fall. Less jobs and plunging house prices have changed family spending.

“We’re excited that Mike got into eight great schools,” said Mike’s father, an engineer at Microsoft. “But if you consider going to school out of state, you’ve got to think about all of the other costs: moving, flying back and forth for the holidays. You’re looking at about $3,000 a year, just for travel.”

As families weigh their choices, some are going back to financial aid offices hoping help packages can be increased.

Rachel Brown was happy to get a thick envelope from New York University (NYU). Although she has always wanted to live in Manhattan, she is seriously considering the University of California San Diego (UCSD), because of the high cost in New York.

“The tuition for NYU is twice as much as UCSD,” said Rachel, 17. “My mom doesn’t want me to have a big debt when I graduate, and I don’t want that either. I’d have to take out a loan of $15,000. I’ll check and see if there’s any way that NYU can offer me any financial aid.”

More than 7.6 million American students have filled out the Free Application for Students Aid, a 19.9 percent increase over last year.

This month the Federal Department of Education urged college financial aid officers to give more help to certain families. A record 30,428 students applied for 2,300 places at Stanford, partly because the university increased financial aid for families earning below $10,000.

68. Mike may give up Notre Dame because of ______.

A. travel fees                                                           B. financial concerns

C. poor exam results                                             D. worries about living far away from home

69. The phrase “Big envelope” in paragraph 2 probably refers to “______”.

A. A text message                                                  B. A large gift package

C. An admission letter                                          D. A scholarship letter

70. What can we learn from the passage?

A. The number of American senior students applying for financial aid is increasing.

B. Rachel Brown has given up NYU because of its high tuition and big debts.

C. It is inevitably hard for college students to borrow money to cover costs.

D. An interest-free loan for students helps more students apply for Stanford.              

71. The passage mainly focuses on ______.

A. the calculation of different costs including tuition

B. the extremely hard financial situation in America

C. the excitement of students’ being able to enter ideal colleges

D. the financial crisis of families over college entrance

题型:判断题

主轴瓦烧熔时是()的结果。

A.干摩擦

B.边界摩擦

C.液体摩擦

D.混合摩擦

题型:判断题

从陆地吹向海洋的风,称为离岸风,反之称为迎岸风。下图为“世界部分地区离岸风和迎岸风分布示意图”,图中箭头表示风向。读图回答下列各题。

在北京的小红与在纽约(西五区)的小明于北京时间5月4日22时结束在网上交谈,并相约于纽约时间5月4日23时再谈。他们两次网上交谈的时间间隔是()

A.1小时

B.13小时

C.14小时

D.25小时

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