A wheel is any dish like object that can be used for transportation or in machinery. To be useful, a wheel must revolve (1) an axle, which is normally a shaft attached (2) the wheel’s center.
No one is exactly sure when the wheel was first (3) . But it is thought to have been in use during the early Bronze Age in the Tigris-Euphrates Valley in the Middle East— (4) Iraq is located today. We know that ancient people there used (5) . These and other wheeled vehicles are shown in artwork from the area (6) back to 3500 B.C.
How were such (7) developed The idea began when people placed logs as rollers under a platform. They were used to (8) heavy loads. The center of the logs may have been partly hewn, or carved away, (9) a narrow axle between solid, thick wheels at each end. Some ancient Middle East people even wrapped leather tires around the solid wooden wheels attached to
A. dug
B. painted
C. shaped
D. baked
| In the world of management, employees
are nonexempt or exempt, depending on whether they get paid for overtime or
not. (21) a creative scientist, like a creative artist, does
not see his or her time. The very idea of a creative scientist (22)
out time sheets is ludicrous. Fascination in science cannot be turned
on or off on (23) The creative mind continues to wander
(24) the body eats, exercises, or sleeps. Interruptions in or
out of the laboratory, the library, the office or the home study may
(25) a promising effort. (26) the
well-established practice of moonlighting. Do what you need to do to keep the
wolf (27) from the door, the world (28)
your thesis adviser, team leader, or laboratory director. Then use the
rest of your time, perhaps at night or on the weekends, to do (29)
you r A. completely B. occasionally C. profoundly D. rarely [单选题] 下列( )属于施工蓝图。
A. 招标图 B. 初步设计图 C.施工图 D. 竣工 [不定项选择题]A.锋电位
A.阈电位 B.后去极化 C.阈刺激 D.阈强度 E.衡量组织兴奋性高低的常用指标是 [单项选择]配筋砌体中受力钢筋的连接方式及锚固长度、搭接长度应符合设计要求。每检验批抽查不应少于（）处。
A. 3处 B. 5处 C. 6处 D. 10处 [单项选择]125I的半衰期
A. 6年 B. 2年 C. 1年 D. 半年 E. 60天 [单项选择]关系数据库中，实现表与表之间的联系是通过( )。
A. 实体完整性规则 B. 参照完整性规则 C. 用户自定义的完整性 D. 值域 [单选题]治疗与醛固酮升高有关的顽固性水肿应选用( )。
A.甘露醇 B.氢氯噻嗪 C.螺内酯 D.呋塞米 [单选题]不具备载客条件的列车上线运营属于（ ）
A.A、一般事件C类 B.B、一般事故C类 C.C、一般事件B类 D.D、一般事件A类。 [单项选择]目前在国标中还不存在的光纤种类为（）。
A. G.652 B. G.654 C. G.659 D. G.655 [单选题](49738)N1601型轨道起重机工作高度,副钩最大工作高度为( )m。
A.12.50 B.16.50 C.18.50 D.20.00 [多选题]在一定季节和区域内不易腐烂、变质、冻损的易腐货物，经（ ）和（ ）协商一致后，在保证不影响货物质量的前提下，可使用通用集装箱装运。
A.托运人 B.发站 C.承运人 D.到站 [单选题]工程变更往往会对工程费用和工程工期带来影响，（ ）应组织相关人员对工程变更费用及工期影响作出评估。
A.总监理工程师 B.建设单位 C.施工单位 D.专业监理工程师 我来回答: 提交
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