下列哪个语句实现将计算机系学生各科成绩置为0？ ( ) (A) update sc set grade=0 where sc.sno=student.sno and sdept=’cs’ (B) update sc set grade =0 where sno in(select sno from student where sdept=’cs’) (C) update grade=0 from sc where sno in(select sno from student where sdept=’cs’) (D) update grade=0 from sc where sdept=’cs’
