昆虫触角类型的变化多发生在() ["柄节","梗节","鞭节","索节"]
秦兵马俑出土的青铜剑和铜簇为什么光亮如新,没有生锈?
装卸桥检修后,应大车不啃道,即车轮轮缘与轨道没有挤压磨损,二者至少应留有()的间隙。 ["0.5~1mm","1~2mm","2~3mm","3~4mm"]
积极引导农村工商企业向有条件的小城镇集中,以“园区”()为载体培育发展农村工商企业集群 ["区县特色工业园区","中小企业创业基地","小企业创业基地","都市工业园","农产品加工创业基地","农产品创新技术基地"]
直径大于6mm钻头,都应修磨横刃,而修磨后的横刃长应为原长的()。 ["1/2~1/3","1/4~1/5","1/2~1/4","1/3~1/5"]
PH计冲洗子组启动步骤