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SiO2+2C 高温__ Si+2CO↑.下列分析正确的是( )
(1)解不等式:1-2x+13≥1-x2;
(2)用配方法解方程:x2+4x﹣1=0.
一What do you do on the weekend? ( )
一I love sports.I often on the weekend.
生物的多样性不包括( )