皮皮学，免费搜题
登录
搜题
【单选题】
下列关于凸轮机构描述正确的是 ( )A.
滚子从动件的凸轮机构承载力大，可以高速转动
B.
凸轮机构推，只有压力角α≤ 30 °，才能避免发生自锁现象
C.
等加速等减速运动的凸轮机构，在速度转折点会发生柔性冲击
D.
柱体凸轮机构得到较大的行程，必须增大圆柱的直径
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】In the eyes of the governors, for the American universities to remain the best in the world, they must______.
A.
get enough funding from the states
B.
undergo serious reform. and adjustment
C.
meet the demands of the global economy
D.
put greater demands upon their students
【简答题】反映轻重、松密、含水程度等这些性质的指标依次有()、()、()等。
【简答题】Italy was dubbed the worl d’ s “ ”
【单选题】下列哪项描述不是中等量心包积液的表现:
A.
M型超声心动图，左心室后壁无回声宽度约1.0cm – 2.0cm
B.
在心包积液中出现“荡击波”征
C.
二维超声整个心包腔均可探及液性无回声
D.
M型超声右室前壁活动幅度增加
【单选题】Anna was reading a piece of science fiction, ____ completely to the outside worl
A.
having been lost
B.
to be lost
C.
losing
D.
lost
【单选题】A potential factor affecting scientists in their efforts to control the overgrowth of world population is that
A.
state administrators do not have confidence in their work.
B.
humanists usually cannot cooperate well with them.
C.
they haven't been trained to consider social effects of their work.
D.
they do not have enough time to tackle the problem.
相关题目：