33. He was interested ____ books. A. in B. about C. over D. on ...
23. If you work hard ________, you won't have to sit up all night before the exam. A. by yourself B. at other times C. willingly D. with some help ...
13. People are more _____ to spend money on goods with an attractive look than those without. A. tempted B. attracted C. tended D. persuaded ...
3. Without water, there ____ no plants. A. would have B. would be C. were to be D. were ...
33. He studied hard in his youth, __________ contributed to his great success in later lif## A. that B. it C. what D. which ...
23. People are more _____ to spend money on goods with an attractive look than those without. A. tempted B. attracted C. tended D. persuaded ...
13. I don’t know why she avoids _______her opinion on the subject. A. to give B. to be given C. giving D. being given ...
3. _______, man could not live at all. A. were it not for the sun B. If it was for the sun C. Had it not been for the sun D. If it shouldn’t be for the sun. ...
33. _______ majority of people are highly against the pollution in this city. A. -- B. A C. The D. Many ...
23. When I saw Jerry, I stopped and smiled but she _______ me and walked on. A. refused B. ignored C. denied D. missed ...
13. He _____ me do the work. A. gave B. helped C. minded D. cared ...
3. I don’t know why she avoids _______her opinion on the subject. A. to give B. to be given C. giving D. being given ...
33. Mr. Smith left for New York long ag##That’s a pity I wish_____. A. I meet him B. I'll have met him C. I'd have met him D. I'll meet him ...
23. The red rose is her __________. A. favor B. favorite C. like D. best ...
3. Without my glasses I can hardly _______ what has been written in the letter. A. make for B. make up C. make out D. make over ...
33. I wish that the train __ soon. A. stopped B. will stop C. would stop D. had stopped ...
23. If the man __________ succeed, he must work as hard as he can. A. will B. is to C. is going to D. should ...
13. The airplane arrived one hour behind ________. A. timetable B. plan C. date D. schedule ...
3. Physics______ interesting subject. A. is an B. are an C. is a D. are a ...
33. With the population explosion, scientists will have to _________ new methods of increasing the world's food supply. A. lead to B. carry out C. come up with D. stick to ...
23. Four hours______ too long for him to write the letter. A. has B. are C. is D. have ...
13. If I fail,I can but ____ that money. A. lose B. to lose C. lost D. losing ...
3. It was not a serious accident; the car needs only some _________ repairs. A. major B. secondary C. minor D. primary ...
33. What we would like you to know is that we greatly _____ your timely help. A. attach B. thank C. appreciate D. compliment ...
23. --- What day is today? --- ________. A. Today is March 25th B. Today is Saturday C. Today is fine D. Today is cold ...
13. They desire nothing but____ hom## A. going B. go C. to go D. to have gone ...
3. This ticket _______ you to a free meal in your new restaurant. A. gives B. entitles C. grants D. credits ...
33. Don't ____ the matter, we can do it right now. A. leave on B. leave over C. leave in D. leave out ...
23. The airplane arrived one hour behind ________. A. timetable B. plan C. date D. schedule ...
13. It took him several months to _____ the wild hors## A. tend B. cultivate C. breed D. tame ...
3. I wish that the train __ soon. A. stopped B. will stop C. would stop D. had stopped ...
3. 流体在管道中作稳定流动时,同一时间内流过管道每一截面的质量相等。 A. 错误 B. 正确 ...
8. 相对压力是()和()之差 A. 绝对压力 B. 大气压力 C. 表压力 ...
13. 变量泵是指( )可以改变的液压泵 A. 排量 B. 功率 C. 扭矩 D. 流量 ...
3. 对于一定质量的气体,在温度不变的情况下,将绝对压力为P1=100MPa,体积为1m3的气体压缩到0.2m3,那气体的绝对压力为( )MPa。 A. 500 B. 100 C. 200 D. 150 ...
3. 旁通型调速阀用于调速时,只能安装在执行元件的进油路上 A. 错误 B. 正确 ...
8. 根据节流阀或调速阀在回路中的安装位置不同节流调速回路可以分成( )节流调速、( )节流调速及( )节流调速三种基本形式。 A. 进油 B. 回油 C. 旁路 D. 旁通 ...
13. 双活塞杆液压缸,采用活塞杠固定安装,工作台的移动范围为缸筒有效行程的( ) A. 1倍 B. 2倍 C. 3倍 D. 4倍 ...
3. 马赫数是表示气流流动的一个重要参数,集中反应了气流的压缩性。马赫数越大,气流密度变化越大。当马赫数( )时称为亚声速流动 A. 大于1 B. 小于 C. 等于1 D. 不一定 ...
3. 液压换向阀的“通”和“位”和中位机能是换向阀重要参数,“H”型中位机能就是A、B、P、O油口全部连通。 A. 错误 B. 正确 ...
8. 压力控制回路包括: A. 调压回路 B. 减压回路 C. 增压回路 D. 保压回路 ...
13. 变量泵是指( )可以改变的液压泵 A. 排量 B. 功率 C. 扭矩 D. 流量 ...
3. 液压泵在转速为950 RPM时的理论流量为160 L/min;在额定压力为295×105 Pa 同样转速下测得流量为150 L/min。则泵的容积效率是: A. 90% B. 80% C. 93.75% D. 60% ...
3. 热交换器是冷却器和加热器的总称,冷却器一般安装在回油管路或低压管路上。 A. 错误 B. 正确 ...
8. 顺序动作回路的功用在于使几个执行元件严格按预定顺序动作,按控制方式不同,分为( )控制和( )控制。 A. 压力 B. 行程 C. 速度 D. 位置 ...
13. 下列哪个器件不属于气动执行元件() A. 单活塞式气缸 B. 双活塞式气缸 C. 膜片式气缸 D. 空气压缩机 ...
3. 流量连续性方程是( )在流体力学中的表达形式 A. 能量守恒定律 B. 动量定理 C. 质量守恒定律 D. 其他 ...
3. 变量泵容积调速回路是指通过改变液压泵(马达)的流量调节执行元件的运动速度或转速的回路。 A. 错误 B. 正确 ...
8. 顺序动作回路的功用在于使几个执行元件严格按预定顺序动作,按控制方式不同,分为( )控制和( )控制。 A. 压力 B. 行程 C. 速度 D. 位置 ...
13. 液流流经薄壁小孔的流量与小孔通流面积的()次方成正比 A. 一 B. 二 C. 三 D. 四 ...
3. 双活塞杆液压缸,采用活塞杠固定安装,工作台的移动范围为缸筒有效行程的( ) A. 1倍 B. 2倍 C. 3倍 D. 4倍 ...
3. 液压泵的排量与泵的转速成正比。 A. 错误 B. 正确 ...
8. 压力控制回路包括: A. 调压回路 B. 减压回路 C. 增压回路 D. 保压回路 ...
13. 液压泵在转速为950 RPM时的理论流量为160 L/min;在额定压力为295×105 Pa 同样转速下测得流量为150 L/min。则泵的容积效率是: A. 90% B. 80% C. 93.75% D. 60% ...
3. 液压泵在转速为950 RPM时的理论流量为160 L/min;在额定压力为295×105 Pa 同样转速下测得流量为150 L/min。则泵的输出功率是: A. 73750 B. 74000 C. 75000 D. 76000 ...
3. 调压回路的功能在于调定或限制液压系统的最低压力。 A. 错误 B. 正确 ...
8. 液压系统对密封装置的要求有: A. 在一定的工作压力和温度范围内具有良好的密封性能 B. 密封装置与运动件之间摩擦因数小 C. 耐磨性好,寿命长,不易老化 D. 制造容易,维护、使用方便 ...
13. 液压传动主要是以液体的( )传递动力 A. 动能 B. 压力能 C. 势能 D. 内能 ...
3. 液压泵按其()分为变量泵与定量泵 A. 排量 B. 流量 C. 工作压力 D. 液压油流速 ...
3. 粘度与温度的关系,温度升高,粘度下降 A. 错误 B. 正确 ...
8. 理想流体是:()、() A. 有粘性 B. 不能压缩 C. 无粘性 D. 能压缩 ...
13. 下列哪个器件不属于气动执行元件() A. 单活塞式气缸 B. 双活塞式气缸 C. 膜片式气缸 D. 空气压缩机 ...
3. 液压泵的实际流量比理论流量( ) A. 大 B. 小 C. 不一定 ...
3. 理想流体伯努力方程的物理意义是:在管内作稳定流动的理想流体,在任一截面上的压力能、势能和动能可以互相转换,但其总和不变。 A. 错误 B. 正确 ...
8. 液压系统对密封装置的要求有: A. 在一定的工作压力和温度范围内具有良好的密封性能 B. 密封装置与运动件之间摩擦因数小 C. 耐磨性好,寿命长,不易老化 D. 制造容易,维护、使用方便 ...
13. 液压马达实际流量比理论流量( ) A. 大 B. 小 C. 不一定 ...
3. 流体流动时,由层流变成紊流的条件由临界雷诺数数决定,当雷诺数()临界雷诺数为紊流。 A. 小于 B. 大于 C. 等于 D. 不一定 ...
3. 热交换器是冷却器和加热器的总称,冷却器一般安装在回油管路或低压管路上。 A. 错误 B. 正确 ...
8. 选用液压油应该考虑: A. 液压系统工作压力 B. 环境温度 C. 执行元件运动速度 D. 液压泵的类型 ...
13. 液压传动主要是以液体的( )传递动力 A. 动能 B. 压力能 C. 势能 D. 内能 ...
3. 液压泵的实际流量比理论流量( ) A. 大 B. 小 C. 不一定 ...
8. 平衡重主要用来平衡发动机不平衡的离心力和离心力矩 A. 错误 B. 正确 ...
13. 配气相位角包括() A. 进气提前角 B. 排气提前角 C. 进气迟闭角 D. 排气迟闭角 ...
3. 为了保证高速柴油机正常高效的工作,轻柴油应具备良好的() A. 发火性 B. 蒸发性 C. 低温流动性 D. 粘度 ...
8. 发生表面点火的原因() A. 燃烧室内炙热面点燃混合气 B. 气体压力温度过高在燃烧室内离点燃中心较远处的末端可燃混合气的自燃 C. 火花塞放电点火 D. 被压燃 ...
8. 冷却液可以使用普通的自来水 A. 错误 B. 正确 ...
13. 当发生爆燃时() A. 火焰以及高的速度传播 B. 温度和压力急剧升高 C. 形成压力波以声速向前推进 D. 伴有强烈的敲击声 ...
3. 减少进气门座处的流动损失的措施有 A. 增大进气门直径,选择合适的排气门直径 B. 增加气门的数目 C. 改善进气门处流体动力性能 D. 采取较小的S/D值(短行程) ...
8. 汽车操纵稳定性的重要表征就是汽车的( ) A. 频域响应 B. 时域响应 C. 稳态响应 D. 瞬态响应 ...
13. Although the pay is not good, people usually find social work _______ in other ways. A. payable B. respectful C. grateful D. rewarding ...