单项选择题
A.1/4~1/5B.1/2~1/3C.1/6~1/7D.1/9~1/10
A.0.1~0.4B.0.2~0.5C.0.5~0.7D.0.7~0.9
A.内缘B.外缘C.中部
A.轴承B.活塞C.电磁阀D.面板
微信扫一扫,加关注免费搜题