— are you going now? —I'm going to go to school. [ ]
A. Who
B. Where
C. What
答案:B
若⊙O1和⊙O2相交于点A、B,且AB=24,⊙O1的半径为13,⊙O2的半径为15,则O1O2的长为( )或( ).(有两解)
“平南三利”小刀因美观、耐用、锋利而驰名区内外,其制作材料“钢”属于[ ]
A.无机非金属材料
B.金属材料
C.复合材料
D.有机合成材料