【单选题】
有关系SC（S_ID，C_ID，AGE，SCORE），查找年龄大于22岁的学生的学号和分数，正确的关系代数表达式是( )。ⅰ.πS_ID，SCORE (σ age>22 (SC) ) ⅱ.σ age>22 (πS_ID，SCORE (SC) )ⅲ. πS_ID，SCORE (σ age>22 (πS_ID，SCORE，AGE (SC) ) )
①
ⅰ和 ⅱ
②
只有ⅱ正确
③
只有 ⅰ正确
④
ⅰ和ⅲ正确
【单选题】
Mr. Wang, _________, is coming up to us.
①
slowly
②
our new teacher
③
he is our new teacher
④
slow
【单选题】
At this moment she____________ a pilot coming in.
①
recovered
②
bought
③
noticed
④
wanted
【单选题】
-- Im taking my driving test tomorrow.-- _________ !
①
Cheers
②
Congratulations
③
Come on
④
Good luck
【单选题】
TOEFL is a test for students __________ native language is not English.
①
that
②
of whom
③
whose
④
which