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等电位作业人员在作业中严禁用酒精、汽油等（）擦拭带电体及绝缘部分，防止（）。

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装载木材时，紧靠支柱的原木，其树节、枝桠、弯曲部分或根部，（）允许超出支柱。

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某厂一台1000MW机组，2007年B级检修47天，节日检修3天，其余时间全出力运行。当年机组计划停运系数是（）。

A. 11.88%
B. 12.88%
C. 13.15%
D. 13.70%

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当一日内水位较大时，由水位查水位流量关系曲线以推求日平均流量，其水位是用（）

A. 算术平均法计算的日平均水位
B. 12时的水位
C. 面积包围法计算的日平均水位
D. 日最高水位与最低水位的平均值

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You have enabled the Slow Query Log for a short period. When you process the Slow Query Log, you receive the following snip of output: Count: 100 Time=0 .22a (22s) Lock=0.00s (0s) Rows=0.0 (0), root[root] @localhost CREATE TABLE 't1' (id serial,id0 varchar(N) unique key,intcaoll INT (N) ,intco12 INT(N) ,intco13 INT(N) ,intco14 INT(N) ,intco15 INT(N) ,charcol1 VARVHAR(N) ,charcol2 VARCHAR(N) charcol3 VARCHAR (N) ,charcol4 VARVHAR(N) ,charcol5 VARCHAR(N) charcol6 VARCHAR (N) ,charcol7 VARVHAR(N) ,charcol8 VARCHAR(N) charcol9 VARCHAR (N) .charcol 10 VACHAR (N) ) Count: 64000 Time-0.02s (1213s) Lock=0.00s (6s) Rows=1.0 (64000), root [root]@ localhost SELECT intocl1, intco12, intco13, intco14, intco15, intco16,intco17, intco18 ,intcol9, intcol10, charcol1, charcol2, charcol3, charcol4, charcol5, charcol6 ,charcol7, charcol8, charcol9, charcol10 FROM t1 WHERE id = 's' Count: 1 Time=0.02s (0s) Lock=0.00s (0s) Rows=1.0 (1) agent [agent] @localhost SELECT Select_priv, Repl_client_priv, Show_db_priv, Super_priv, Process_priv FROM mysql.user WHERE CONCAT (user, 's', host) = CURRENT_USER () Count: 48000 Time=0.02s (778s) Lock=0.00 (3s) Rows=1.0 (48000), root[root]@localhost SELECT intocl1,intcol2,intcol3, intcol4, intcol5, charcol1, charcol2, charcol3 ,charcol4, charcol5, charcol6, charcol7, charcol8, charcol9, charcol10 FROM t1 WHERE id = 's' You want to tune the query such that it provides the greatest overall time savings. Which query will accomplish this?（）

A. CHEATE TABLE 't1' (id serial, id0 varchar (N) unique key, intcol1 INT (N) ,intcol2 INT (N), intcol3 INT(N) ,intcol4 INT(N), intcol5 INT(N), charool1 VARCHAR (N) ,charcol2 VARCHAR (N), charcol3 VARCHAR(N), charcol4 VARCHAR(N), charcol5 VARCHAR (N) ,charcol6 VARCHAR (N), charcol7 VARCHAR(N), charcol8 VARCHAR(N), charcol9 VARCHAR (N) ,charcol10 VARCHAR (N)
B. SELECT intcol1, intcol2, intcol3, intcol4, intcol5, intcol6, intcol7, intcol8, intcol9, Intcol10, intcol11, intcol12, intcol13, intcol14, intcol15, intcol16, intcol17, intcol18, intcol19, charcol10 FROM t1 WHERE id = 's'
C. SELECT Select_priv, Repl_client_priv, Show_db_priv, Super_priv, Process_priv FROM mysql.user WHERE CONCAT (user,'s', host) = CURRENT_USER()
D. SELECT intcol1, intcol2, intcol3, intcol4, intcol5, charcol1, charcol2, charcol3, charcol4, charcol5, charcol6, charcol7, charcol8, charcol9, charcol10 FROM t1 WHERE id = 's'

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