在SQL中,insert、update和delete分别为对基本表进行______、______和______记录操作的命令。
参考答案:插入、修改(更新)、删除
-What did you think of ______ president?-I didn’t care for him at first,but after ____ time I get to like him.
A.the; a
B./; the
C.the; the
D./; a
一只标有“220V 100W”的电热器接在110V的电源上,如果不计电阻变化,则此电热器的实际功率为( )
A.100W
B.25W
C.50W
D.20W