世界上最大的货物出口国是（　　）

阅读下面短文, 从短文盾所给的A、B、C三个选项中能填入相应空白处的最佳选项, 并在答题卡上将相应的字母编号涂黑。

    Almost everyone has a mobile phone, but have you ever thought that cell phones might be 1 for your health? A study shows that heavy mobile phone use may cause hearing loss and people can't hear clearly.

    This study shows that people who use cell phones for about an hour a day have a 2 time hearing some similar sounds, especially in their right ears. It is getting harder for 3 to tell the differences between the sounds of “s” and “f”, and “t” and “z”.

    Researchers studied 100 people who used cell phones and 4 them with 50 people who did not. The study lasted for l2 months. What the researchers found was that cell phone users had more hearing 5 than those who did not use cell phones.

    Our ears have many little 6 inside them. Too much noise will cause these hairs to get weak and 7 die. When these hairs die, it affects our ability to listen.

     However, cell phone users don't care too much 8 this study. One man said, “I'd be more worried about people who 9 MP3 players. They put those earphones in their ears and enjoy very 10 music. I think that is more likely to cause hearing loss than a cell phone.”