下列各句中，没有语病的一项是（    ）

阅读《新型材料》，回答问题．

《新型材料》

如图所示是科技馆内展示的新型材料：纳米材料、复合材料和双向记忆合金．

纳米材料是指由颗粒尺寸在 1﹣﹣100nm 之间的超微颗粒组成的材料．纳米是一个极小的长度单位，当材料颗粒小至纳米级别时，会赋予该材料很多特有的性质，是普通材料无法比拟的．

复合材料是两种或两种以上不同性质的材料，通过物理或化学的方法，在宏观（微观）上组成具有新性能的材料．从古至今沿用的稻草增强粘土和已使用上百年的钢筋混凝土均由两种材料复合而成，也是复合材料．由于复合材料的重量轻、强度高、加工成型快、耐腐蚀性能好等特点，不仅广泛应用于汽车、健身器材、建筑、家居等方面．随着现代科技的发展，复合材料在航空工业上也起到十分重要的作用．

用酒精灯给双金属片加热，双金属片发生弯曲，原来这个受热弯曲的金属片是由两种不同的金属贴合而成的，各种金属都有热胀冷缩的特性，而不同的金属随着温度变化热胀冷缩的程度不同，金属片于是就会发生弯曲．例如铁片和铜片组成的双金属片，铜片的膨胀系数比铁片大，温度高时，膨胀得比铁片多，就会弯曲．双金属片的这种性质在生活中有很多应用．

阅读理解，请阅读材料，完成后面的1-5题。

I remember when I was growing up ,my mom always said ,“Half the fun of doing anything is sharing it with others .” It's so true .Friends allow us to enjoy the taste of our success and our joys and comfort us in our challenging moments. They provide a mirror for us to learn more about ourselves .I've always looked at friends as the family members.They enrich our lives .As Robert Louis Steven once said,"A friend is a present which you give yourself."

To be a good friend，①成为一个好的听众是很重要的.Hear what your friend says first rather than making conclusions（结论）quickly. Sometimes it is useful to repeated their words back to them， it can help them to realize whether their words were what they wanted to say.

Patience is also important in being a good friend. You know the old golden rule, “Care for others they way you would like them to care for you.”The support of a friend during a difficult time could make the difference between success and failure. ② Encouragement and confidence are the best gifts that can change a person's life.

We should choose our friends carefully, because they can have a huge effect on our life. As someone told me“The attitudes of your friends are like the button(按钮) on a lift. They will either take you up or down.

以直角三角形的三边为边长分别向外作正方形，已知其中两个正方形的面积分别为20和16，则第三个正方形的边长为（       ）

—I have trouble learning math this term.

—You should pay more _______ to your teacher's advice.