保持泥浆中土粒悬浮状态的指标是( )。A．相对密度 B．黏度 C．含砂率 D．胶体

Observe that for the programmer, as for the chef, the urgency of the patron（顾客）may govern the scheduled completion of the task, but it cannot govern the actual completion. An omelette（煎鸡蛋），promised in two minutes, may appear to be progressing nicely. But when it has not set in two minutes, the customer has two choices-waits or eats it raw. Software customers have had __(1)__ choices. Now I do not think software __(2)__ have less inherent courage and firmness than chefs,nor than other engineering managers. But false __(3)__to match the patron's desired date is much more common in our discipline than elsewhere in engineering. It is very __(4)__ to make a vigorous, plausible, and job risking defense of an estimate that is derived by no quantitative method, supported by little data, and certified chiefly by the hunches of the managers. Clearly two solutions are needed. We need to develop and publicize productivity figures,bug-incidence figures, estimating rules, and so on. The whole profession can only profit from__(5)__such data. Until estimating is on a sounder basis, individual managers will need to stiffen their backbones and defend their estimates with the assurance that their poor hunches are better than wish derived estimates.

空白（4）处应选择（）

A.easy 

B.difficult 

C.simple 

D.painless

某县农贸市场内，菜贩丁因气恼顾客被隔壁摊位菜贩甲之妻乙抢走，与乙发生口角并打架。被拉开后，甲赶来先动手揪住丁的头发互相厮打，菜贩戊、己见状赶忙劝架，在拉扯中，戊被甲、丁一带，立足不稳，向后跌倒，后脑正好撞在一块石头上，当即出血昏迷，被众人送往医院。经法医鉴定，其损伤已构成人体轻伤，但不构成伤残。己将乙拉走，甲也跟着离开。之后，甲之弟丙闻讯赶来，向丁叫嚣，丁未理会。后甲、乙回到摊位。10分钟后，丁来到甲摊位质问丙什么意思，丙见丁的手插在裤兜里，好像有东西，便突然上去踹丁一脚，随后甲抱住丁，双方互相厮打。甲拿起一啤酒瓶照丁的头部打击，致丁头部外伤出血，后丁去医院就诊，经医生诊断为头皮裂伤，住院11天。事发后，该县公安局对此事作出处理，戊也将甲、丁告上法庭，要求二人赔偿医疗费、误工费、营养费、精神抚慰金等共计2. 12万元。两被告究竟谁是推倒戊的“真凶”，两被告均否认是自己推倒了戊，并提供了相应的证据。请运用你所学法律知识，对该案所涉及的法律问题进行全面分析。

关于液压操动机构维修、调整下面说法中错误的是（）。

A.检修机构时，应十分注意机构的清洁度

B.环境温度过低时，应起动加热器，以保证液压油的流动性，否则将影响断路器的分、合闸速度及密封的可靠性

C.正常情况下，油泵每十天启动一次，若起动次数过多，说明高压油路渗油过快，密封损坏，要及时修理

D.断路器在正常工作中，若机构失压，可采用机械闭锁工具（如卡板）卡在水平连杆的接头上，使断路器维持在合闸状态，再检修机构

氨与氟、氯等接触会发生剧烈的（）。