— ________ is your new bike?
— I ________ about 900 yuan for it.
A:How many; paid
B:How much; paid
C:How much; took
已知` |a→|=1 , |b→|=2 ,若 (a→+b→)⊥a→ ,则 a→ 与 b→ 的夹角为( )
读课文《小母鸡种稻子》,小母鸡种稻子一点儿也不怕辛苦。