My name is Tom. My best friends are John and Ann. John lives near my house and we are in the same class. He’s tall and thin, he has blonde hair and blue eyes. He is polite and very clever. He is very good at math and sometimes helps me with my homework sometimes. He usually wears jeans and a blue T--shirt. We three often play basketball in a nearby park.
   My friend Ann studies at another school.She’s short and slim(苗条的) with straight brown hair and brown eyes. She’s a little bit shy. We all have Kong fu lessons every Tuesday and Friday afternoon. We love Kung fu very much. Ann is really good at Kung fu. We call her the “Kong fu girl”. Sometimes she practices Kung fu with us. She loves wearing a T—shirts and a hat. The three of us have great fun together.

2009年,美国著名未来学家约翰乃尔比特在他的新著《中国大趋势》中认为：中国没有以民主的名义使自己陷入政党争斗的局面，而是以一党体制实现现代化，发展出一种独特的纵向民主，形成稳定的关键。这里的“中国没有……陷入……争斗的局面”和“一党体制”是指

对下列句子中划线词语的解释不正确的一项是(　　)

学习了塑料、纤维、橡胶以后，某化学兴趣小组想设计实验证明做食品袋的塑料具有热塑性．

【实验用品】试管、剪刀、食品袋．还需要的仪器是 （1） ____、（2） ____．

【实验步骤】剪取少量食品袋碎片，加热，观察到碎片开始软化，后熔化．然后停止加热，冷却，观察到固化．

【实验结论】（3） ____．

【问题讨论】出现以上现象的根本原因是（4） ____