上图中阀1为定量泵，主要作用是为系统提供能量和动力的。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201905/838994688e7b434fa9fcb5b6e2ffb82f.png
举一反三
- 上图中阀1为定量泵，主要作用是为系统提供能量和动力的。http://image....a9fcb5b6e2ffb82f.png
- 若x2+y2=1，则dy为（ ） A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201905/d045b5f235a54083ab91e6f717cf00d8.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201905/74173c5355234874ab8cb9275865d5d6.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201905/bbfb37ba58fc4de0aa8688e0bb53cef5.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201905/f9a206c25e8c4ea1bd7b51519afd76b7.png" />
- 上图中阀7和阀8位节流阀，主要作用是控制系统执行元件液压缸运动速度快与慢的。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201905/a788334b8ece417fbface7c2bd566106.png
- 上图中阀3为直动型溢流阀，主要作用稳压溢流，保护系统安全的。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201905/9897d47243c7415d8bdc94066ae81c7e.png
- Photoshop中，图像的透明部分会表示为（ ） A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201905/4e20cc22fa2d419b927fba9a72c9da1b.jpg" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201905/fe4f3b584da94076a934d71eb300a12a.jpg" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201905/a6f4e75987e54a8399f598f3eef69516.jpg" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201905/777cf882eb0e439b80358516831b1526.jpg" />