设a，b，l均为不同直线，α，β均为不同平面，给出下列3个命题：

①若α⊥β，a⊂β，则a⊥α；

②若α∥β，a⊂α，b⊂β，则a⊥b可能成立；

③若a⊥l，b⊥l，则a⊥b不可能成立．

其中，正确的个数为（　　）

图是菜豆发育过程中的相关结构，以下叙述正确的是（  ）

    Everybody likes music. Everybody can make sounds1a way by singing 2playing an instrument. Many 3 are developing as people find 4 how to sing in different ways. There are many kinds of music5. Then you are sure to find some music that will greatly interest you.

    Music has meaning 6everyone. The old and the young, men and women all 7it. It can 8 people happy or sad. In our modern world, radios and televisions supply us with a constant flow of music, giving us enjoyment.9in a music lesson or at a concert, music means different things to different people. Music belongs to the 10world.