打桩作业时,严禁在桩机垂直半径范围以外和桩锤或重物底下穿行停留。

题型:判断题

问题:

打桩作业时,严禁在桩机垂直半径范围以外和桩锤或重物底下穿行停留。

考点:建筑类企业主要负责人A证考试企业主要负责人A证考试题库
题型:判断题
在“探究加速度与力、质量的关系”的实验步骤中,下列做法中正确的是(  )

A.同时改变拉力 F 和小车质量m的大小

B.先保持小车质量 m 不变,研究加速度 a 与拉力 F 的关系,再保持 F 不变,研究 a 与 m 的关系,最后导出a与 m 及 F 的关系

C.只改变拉力 F 的大小,小车质量 m 的大小始终保持不变

D.只改变小车质量 m 的大小,拉力 F 的大小始终保持不变

题型:判断题

请阅读下列应用文和相关信息,并按照要求匹配信息。

以下是各个电视节目的简介:

A. Wild World-this exciting show takes you around the world to places of unimaginable natural beauty and

     danger. Learn more about our world and see animals as they live in nature.

     Time: Friday 8.30-9.30 pm

B. Sports Sunday-learn what's happening in the world of sport. See how your team performed, find out who

     is playing and watch interviews with all your favourite sports stars.

     Time: Sunday 1-5 pm

C. The Music Man-John Rogers is a musician by day but a secret superhero crime fighter by night in this

     long-running television action drama.

     Time: Weekdays 3.00-4.00 pm

D. Lateline-All the latest news and opinions from around the world. If you want to know where there is

     trouble in the world or the reasons behind the global economic crisis,join our team of award winning

     journalists.

     Time: Weekdays 9-10 pm

E. Entertainment This Week-Covers the world of entertainment. Hear this week's number one song, watch

     the newest movie reviews and listen to all the latest gossip about the stars.

     Time: Saturday 6 pm

F. Pop Star-Hundreds of young and (sometimes) talented performers sing the latest songs and compete to

     see who will become the nation's newest Pop Star.

     Time: Thursday 7.30 pm

以下是每个人的情况介绍,请匹配每个人与其拟选择的电视节目:

( )1. Sarah O'connor. Sarah is trying to decide where she will spend her summer vacation. She has a

            number of different places in mind but is worried about terrorism and her safety so she doesn't

            want to go anywhere that is dangerous or may become dangerous soon.

( )2. John Smith. John loves football and as a senior company manager needs to know the latest economic

            news. He seldom gets home before 10 o'clock at night during the week so he likes to relax in front

            of TV on the weekend.

( )3. Robert Wise. Robert is a fan of action. He loves to watch exciting TV shows whether they are fictional

           or real. He usually only has time to watch TV on weekday evenings as he works during the day and on

           weekends he likes to go hiking and camping.

( )4. Joan Johnson. Joan is a housewife who sometimes feels bored at home so she enjoys watching exciting

            TV shows. When the kids are home on the weekends and after school she never gets a chance to

            watch TV as they want to watch the shows they like.

( )5. Bill West. Bill is a music fan and a musician. He is always trying to hear the newest and most popular

           songs and learn more about his competitors. He is usually free after he finishes work at 5 pm except

           on weekends when he plays with his musical group in a local club.

题型:判断题

如图所示,将半径为R、圆心为O的大圆环固定在竖直的平面内,将两个轻质小圆环套在大圆环上,一根轻质长绳穿过两个小圆环,它的两端都系上质量为m1的重物,忽略小圆环的大小。求:

(1) 将两个小圆环固定在大圆环竖直对称轴的两侧倾角θ=30°的位置上。在两个小圆环间的绳子中点C处,挂上一个质量的重物,使两个小圆环间的绳子水平,然后无初速度释放重物m,设绳子与大、小圆环间的摩擦均可忽略,求重物m下降的最大距离。

(2)若不挂重物m,小圆环可以在大圆环上自由移动,且绳子与大、小圆环间及大小圆环之间的摩擦力均可以忽略,问两个小圆环分别在哪些位置时,系统可处于平衡状态?

题型:判断题

结节性甲状腺肿所以需要手术是因为()。

A.继发甲亢

B.可有恶性变

C.压迫呼吸道

D.合并胸骨后甲状腺肿

E.以上都不是

题型:判断题

通常情况下粒细胞循环池中包括

A.晚幼粒细胞
B.中幼粒细胞
C.早幼粒细胞
D.杆状核粒细胞和分叶核粒细胞
E.原粒细胞

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