A:Al2O3
B:Al2(SO4)3
C:Al(NO3)3
D:Fe(NO3)3
Which of the following is not the city of the USA?
求证:
已知a、b∈R,(a+bi)2=3+4i(i是虚数单位),则a2+b2=____,ab=____.
has have jeans T-shirt friends is