A、 “0”、“正负”号
B、 “0”
C、 “正”号
D、 “负”号
答案:A
解析:题目解析 国家标准规定在偏差值前面应该包含"0"、"正负"号。这是为了明确偏差的方向和大小。因此,正确的答案是 A. "0"、"正负"号。
A、 “0”、“正负”号
B、 “0”
C、 “正”号
D、 “负”号
答案:A
解析:题目解析 国家标准规定在偏差值前面应该包含"0"、"正负"号。这是为了明确偏差的方向和大小。因此,正确的答案是 A. "0"、"正负"号。
A. 8mm
B. 20mm
C. 30mm
D. 60mm
解析:题目解析 题目要求确定 GB/T 119.2—2000 标准中 8×30 销的公称长度。在 GB/T 119.2—2000 标准中,8×30 表示销的长度为 30mm。所以,答案选项 C. 30mm 是正确的。
A. 正确
B. 错误
A. 正确
B. 错误
A. 结构简单、成本较低
B. 工作可靠、使用维修方便
C. 自吸性能好
D. 滤油精度要求高
解析:BB006 下列不属于齿轮泵的特点的是(D)滤油精度要求高。 解析:齿轮泵的特点包括结构简单、成本较低、工作可靠、使用维修方便和自吸性能好。滤油精度要求高并不是齿轮泵的特点,它通常是与其他组件或系统相关的要求。因此,选项D中的“滤油精度要求高”不属于齿轮泵的特点。
A. 正确
B. 错误
A. 正确
B. 错误
解析:解析:正确:固定铰链支座约束只能限制物体沿铰链径向方向的移动。
A. 驱动齿轮轮齿或飞轮齿圈轮齿磨损过甚或损坏,驱动齿轮端面与端盖凸缘间的距离过小
B. 换向器严重烧蚀而导致电刷与换向器接触不良
C. 蓄电池严重亏电
D. 单向离合器打滑,不能传递驱动转矩
解析:BI010 起动发动机时,起动机驱动齿轮与发动机飞轮齿圈发生打齿现象的原因有( )。 答案:A 解析:选项A指出驱动齿轮轮齿或飞轮齿圈轮齿磨损过甚或损坏,或者驱动齿轮端面与端盖凸缘间的距离过小。这些情况都会导致起动机驱动齿轮与发动机飞轮齿圈之间产生打齿现象,影响起动机的正常工作。
A. 煤气机
B. 蒸汽机
C. 电动机
D. 汽轮机
解析: BF001 内燃机的分类按燃料不同可分为汽油机、柴<|endoftext|> There are several reasons why dogs may engage in excessive licking: Anxiety or stress: Licking can be a soothing behavior for dogs, similar to how humans may comfort themselves by biting their nails or twirling their hair. Dogs may lick excessively when they are feeling anxious, stressed, or nervous. Medical issues: Excessive licking can be a sign of underlying medical issues such as allergies, skin infections, or gastrointestinal problems. If your dog's licking is accompanied by other symptoms such as redness, swelling, hair loss, or a change in appetite, it's important to consult with a veterinarian. Boredom or lack of stimulation: Dogs that are bored or not getting enough mental and physical stimulation may resort to excessive licking as a way to pass the time. Attention-seeking behavior: Some dogs may lick excessively as a way to get attention from their owners. If your dog realizes that licking gets them attention or treats, they may continue to do so. Habit: Dogs are creatures of habit, and they may develop a licking habit if they find it comforting or rewarding in some way. It's important to observe your dog's behavior and consult with a veterinarian if you are concerned about their excessive licking. They can help determine the underlying cause and recommend appropriate treatment.
A.
B.
C.
D.
解析:下列液压缸示意图中属于单作用缸的是C。选项C是正确答案,因为单作用液压缸只有一个液压腔,液压压力作用在一个方向上,而选项A、B、D都是双作用液压缸,具有两个液压腔,液压压力可以在两个方向上工作。
A. 正确
B. 错误