有纺土工织物垂直渗透系数要求()。 ["≥5×10-1cm/s","5×10-4cm/s","5×(10-1—10-4)cm/s","≤5×10-1cm/s"]
下述病毒中,属于缺损病毒的是()。 ["HAV","HBV","HCV","HDV","HEV"]
将已定义的图块或图形文件插入到图形中,AutoCAD默认的快捷键是()。 ["Ctrl","In","P","I"]
猪繁殖与呼吸综合征
将5mL10mol/L盐酸稀释为250mL溶液,再从稀释后的溶液中取出10mL溶液的摩尔浓度是(). ["0.08mol/L","0.2mol/L","0.5mol/L","1mol/L"]
中国“30年代电影”