依据《生产安全事故应急条例》，应急救援队伍接到有关人民政府及其部门的救援命令或者签有应急救援协议的生产经营单位的救援请求后，应当立即参加生产安全事故应急救援。应急救援队伍根据救援命令参加生产安全事故应急救援所耗费用，由（ ）承担。

A. desc t1;
B. desc t2;
C. desc t1.t2;
D. desc t2.t1;

A. count()
B. count(*)
C. count(
D. )
E. cuont(*)

A. select * from t1.t2 limit 100
B. select * from t1.t2 limit 100;
C. select * form t1.t2 limit 100;
D. select * from t2.t1limit 100;

A. select uid,keyword from t2 limit 10;
B. select * from t2 limit 10;
C. select from uid,keyword t2 limit 10;
D. select uid,keyword from t2;