针对工程项目,出于安全性考虑,确定变形监测的精度指标一般取允许变形值的()
A.1/10--1/20
B.1/3—1/6
C.1/5--1/10
D.1/2--1/5
参考答案:A
如果QUANTITY的值为空值(null),在执行以下哪个语句时会显示一个0
A.SELECT id_number, 100/quantity FROM inventory;B.SELECT id_number, NVL(100/quantity, 0) FROM inventory;C.SELECT id_number, NULL(100/quantity, 0) FROM inventory;D.SELECT id_number, TO_CHAR(100/quantity, 0) FROM inventory;E.SELECT id_number, NVL(100/quantity, ’999.00’) FROM inventory;
有理数a,b 满足a>0,b<0,|a|<|b|,则a ,b ,-a ,-b的大小顺序是[ ]
A.-a<b<a<-b
B.b<-a<a<-b
C.-a<-b<b<a
D.b<-a<-b<a