机电式程控器通过计时微电机带动一个多阻尼记忆步进(),来实现一组开关按规定时间顺序接通和断开。
A.托盘
B.凸轮盘
C.高速凸轮组
D.低速凸轮组
参考答案:B
短文缺词填空 根据短文内容和所给的首字母,填入单词。
My name is Nick. My family is big. We often have a good time at the w 1 . My mother c 2 for us, but she d 3
wash the dishes. My father washes the dishes. He also c 4 his car. Sometimes, he goes f 5 . My grandparents like
watching TV very much. I don't like watching TV at the weekend. I like c 6 with my friends on the Internet. My
sister Lily l 7 listening to m 8 . She also likes watering the f 9 in the garden. We all e 10 our weekends.
下图中甲乙为两个岛屿,回答1—2题。
1、甲乙两个岛屿的共同点是[ ]
A、都处于板块的消亡边界
B、夏季均盛行西南季风
C、都分布在大西洋中
D、西侧都有盐场分布
2、甲岛森林树种比乙岛丰富的主要原因是 [ ]
A、地跨热量带较多
B、人工引进品种较多
C、东西降水差异
D、植被垂直分异不显著