Yin Ping military attack on North Island was turned into ______ sea of fire in ______ disputed waters near North Korea.

A．a; the

B．不填; a

C．the; the

D．不填; the

某钢铁厂用含杂质19%的赤铁矿冶炼生铁，求8000kg这种矿石可冶炼出含杂质3.5%的生铁多少千克？