根据短文理解，从A、B、C、D四个选项中选择最佳答案填空。

    I have a cousin. 1 name is Eric. He is 2. He likes music and he can play 3 very well. But he 4 want to join the music club. He wants 5 the art club. He wants to learn 6. I don't like music 7 art, I like sports. I can play tennis. I can 8 swim but I can't swim 9. I want to join the sports club. My friends are in that club. I want to play sports with 10.

小明解不等式 $\frac{1+x}{2}-\frac{2x+1}{3}\le 1$ 的过程如图．请指出他解答过程中错误步骤的序号，并写出正确的解答过程．

2012年元月的某一天，我市的最低气温为－3℃，最高气温为4℃，那么这一天我市的日温差是(    )