变压器的短路损耗主要为（）。 ["全部为铜耗","主要为铜耗","全部为铁耗","主要为铁耗"]
Which two statements are correct about database transportation?（） (Choose two.) [" The source and target platforms must be the same"," Redo logs, control files and temp files are also transported"," The transported database must have the same database identifier (DBID) as the source database and cannot be changed"," The COMPATIBLE parameter must be set to 10.0.0.0 or higher and the database must be opened in readonly mode before being transported"," Recovery Manager (RMAN) is used to convert the necessary data files of the database if the target platform is different and has different endian format"]
Evaluate the SQL statement: SELECT LPAD (salary,10,*) FROM EMP WHERE EMP _ ID = 1001; If the employee with the EMP_ID 1001 has a salary of 17000, what is displayed?（） [" 17000.00"," 17000*****"," ****170.00"," **17000.00"," an error statement"]
【背景资料】某工程位于某市的东二环和三环之间，建筑面积4万余m2，由30层塔楼及裙房组成，箱形基础，地下3层，基础埋深为12.8m。该业主在裙房施工竣工后，具备使用功能，就计划先投入使用，主体结构由市建筑公司施工，混凝土基础工程则分包给某专业基础公司组织施工，装饰装修工程分包给市建筑公司施工。其中基础工程则分包于2008年8月开工建设，同年10月基础完工。混凝土强度等级C35级，在施工过程中，发现部分试块混凝土强度达不到设计要求，但对实际强度经测试论证，能够达到设计要求。主体和装修于2008年12月工程竣工。
请根据上述背景资料完成以下选项装饰装修工程中，在贴大瓷砖地面时，一般需弹“十”子线，其作用是（）。 ["A.保证平整度 ","B.方便拼图 ","C.方便找坡 ","D.保证横平竖直"]
市场结构的基本类型有（） ["A、完全竞争市场结构 ","B、完全垄断的市场结构 ","C、寡头垄断市场结构 ","D、垄断竞争的市场结构"]
空气中微生物种类数量最多的（）。
