《舌尖上的中国》有这样的描述：中国拥有世界上最富戏剧性的自然景观…有助于物种的形成和保存，任何一个国家都没有这样多潜在的食物原材料。

如图，已知Rt△ACB中，∠C=90°，∠BAC=45°．

Many students ______ chances to show themselves in class because the class size is too big.

阅读理解

                                                                                      (B)

    Long long ago, there was no paper in the world. People had to write characters(汉字) in bamboo slips or stones.Then there was a man named Cai Lun who was a Chinese man. He made people use all kinds of things to invent paper. From then on, people can use paper to write on. Paper is a great invention. We always remember the great inventor Cai Lun. Nowadays paper is very useful in our work, study and our life. It really means a lot to human beings.

根据短文内容，判断下列句子的正 (A)与误 (B)，并在答题卡的相应位置将其涂黑。