我省宜春某麻纺厂生产的“XX牌”服饰以其美观大方、舒适，为消费者所喜爱．该品牌衬衫的面料成分为“75%苎麻，25%棉”，请问：

（1）该衬衫的纤维种类属于______（填“天然纤维”或“合成纤维”）．

（2）要检验某服装是否用涤纶制成的该品牌衬衫的假冒产品，简便的方法是：______．

根据汉语完成下列句子

1. I spend all my _____ _____(闲暇时间) on football.

2. She _____(周游) the Asia when she was fourteen.

3. The boy began to go to school _____ _____ _____ _____(在……岁时) six.

4. Li Yundi won the first prize in the 14th Chopin _____ _____ _____(国际钢琴比赛)in Poland.

5. I didn't go to the music class _____ _____(由于)the heavy rain.