双梁通用门式起重机和装卸桥主梁上拱度最大值应处在主梁跨中部（）范围内。 ["A、S/10","B、S/15","C、S/20","D、S/25","E、S/5","F、S/3","G、S/4","H、S/6","I、S/2","J、S/7"]
低产桑园的改造措施有（） ["A．压条补株","B．壮苗补缺","C．提高剪定","D．套种更新"]
监狱要根据每一名罪犯的具体情况，实施有针对性的（）。 ["法制教育","政策教育","个别教育","前途教育"]
表明蚕处于求食状态的有哪些？
面料含哪三类？
产生未焊透的原因是什么？
