有些设备需要转速分段运行，而且每段转速的上升、下降时间也不同，为了适应这些控制要求， 发布时间：2017-10-09 13:32 │ 来源：www.tikuol.com 题型：填空题 问题： 有些设备需要转速分段运行，而且每段转速的上升、下降时间也不同，为了适应这些控制要求，变频器具有（）功能和多种加、减速时间设置功能。
题型：填空题 选择单词，用其适当的形式填空，使短文意思正确、通顺。（每词限用一次）back child stay free they have happily like different be There are many different kinds of animals in the zoo. We see the zookeepers give (1)________ food to eat. They don't (2)________ to find food for themselves. They just eat, walk and sleep all day. So many of us think that the animals there (3)________ happy. But most of them are sad. Why? They aren't (4)________! Animals (5)________ monkeys and tigers usually live freely and (6) ________ in forests or mountains. Tigers, for example, run, jump and play with their (7)________ and catch small animals for food. But now they have to (8)________ in the small rooms in the zoo. Their life there is (9)________ from their life in the forests. Now all of us think animals should go (10)________ to the forests. Do you think it is true? 查看答案