A:1.21π
B:2.4π
C:3.6π
D:36π
____
用计算器算出:18千克大米的总价是____元.
用计算器算出:9.5千克大米的总价是____元.
用计算器算出:26千克大米的总价是____元
⑴After I get up, I brush my teeth.
⑵Before I have breakfast, I wash my face and hands.
⑶After I have breakfast, I walk to school.
⑷Before I have dinner, I do my homework.
⑸After dinner, I watch TV.
若a→=(2,﹣1,0),b→=(3,﹣4,7),且(λa→+b→)⊥a→,则λ的值是( )