钢丝绳若有严重的内部和外部(),则应立即报废。 ["腐蚀","穴蚀","点蚀","胶合"]
下列选项中,支持他的制作和播放软件少,且压缩很耗时的音频软件是() ["WMA","MP3","VQF","RAM和RM"]
单体型锚杆钻机又可从动力上区分为() ["A.液压","B.电动","C.风动","D.油动"]
汽车式起重机作业前,应全部伸出支腿,并在撑脚板下垫方木,调整机体使回转支承面的倾斜度在无载荷时不大于()。 ["1/1000","2/1000","3/1000","4/1000"]
种子繁殖的播种期及方式方法如何确定?
提高花卉扦插繁殖成活率的措施有哪些?