【多选题】根据溢流阀在液压系统中所起的作用,溢流阀可作 [填空(1)] [填空(2)] [填空(3)] 和背压阀使用。
【简答题】请将下面的句子翻译成中文: Researchers argues that tourism ually results in net negative impacts for tourism destinations unless careful regulations are put into place.
【多选题】室外排水系统常用的管道常用管材包括 ()
【判断题】Tourism destinations in every corner of the globe have the tendency to experience a disaster of one form or another at certain point in their history.
【单选题】在气-液色谱柱内,被测物质中各组分分离的依据是()
【判断题】FTP 服务器默认使用TCP协议的20、21端口与客户端进行通信
【单选题】当监测的温湿度值超出规定范围时,系统应当至少每隔( )分钟记录一次实时温湿度数据