国道205线XX沿河路段修筑有石笼、丁坝、砌石护坡,并在边坡铺草皮,在河滩大量植树,上述结构和措施属于
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
免费的网站请分享给朋友吧