In the past decade, our education system too much on grades. However, grades have a direct connection with future success is still a question.
A:focused; whether
B:focused; if
C:has focused; whether
D:has focused; if
Kate doesn't____ ____her mother at all.
p1:|z|=2,
p2:z2=2i,
p3:z的共轭复数为1+i,
p4:z的虚部为﹣1.
由于人口增长过快而带来的问题不包括( )