The basketball final between Perfect School and Sunrise School has entered white-hot stage. There are only fifteen seconds left. Sunrise School is one point ahead. Mitchell, who is one of the best players of Perfect School, is now controlling the ball. The students are extremely excited. They cannot help standing up and shouting, “Go! Mitchell!”Other teammates also encourage Mitchell, “Take a shot, boy!”
    Mitchell knows it will be the last shot. He hesitates (犹豫) and falls into careful thinking. He imagines that he shoots from the halfway line. The hall turns quiet. All eyes follow the track of the basketball. It jumps round the ring over and over again and finally rolls out of the court. The world turns noisy. Mitchell sees his coach lower his head, his teammates kneel down and his fans cry. It gives him so much pain. It is the last match for his coach before retiring. All the teammates practiced hard and hoped to give their coach a perfect ending. But now, the bubble bursts (破裂).
    “Is that what you want?” Mitchell asks himself.“Certainly not. But how can I change the situation? Teamwork!”Mitchell returns to reality from his thinking. He does not have a shot by himself but surprisingly passes the basketball to his teammate, Jack, who is standing near the basket. Jack catches the basketball and quickly scores a two-point shot. There goes the whistle at the same time. Perfect School finally wins the game.

常食大蒜能保护心脏．大蒜切开后，其内的蒜素半胱氨酸能在胱硫醚连接酶的作用下分解产生硫化物（如H₂S），具有降低胆固醇的作用．实验表明，经蒜素半胱氨酸处理的动物，左心室肌细胞内胱硫醚连接酶的活性增加，血浆里的增多H₂S，动物的死亡率大为降低．下列相关描述不正确的是（　　）

我国民族分布的特点是（    ）

某中学初三女学生小红，多次受到三个不法分子的勒索。第一次，他们要她交50元“保护费”，声称不给便要打她，不准她上学。于是，她只好把存起来的零用钱，给了他们；三天后，他们又要她交出100元，声称不给便要划破她的脸，她只好偷偷地向别人借钱，凑足钱数给了他们。但过了一个星期，这些人又来胁迫，要她交出500元。一个初中生哪来这么多钱？他们把她劫持到一个旅馆，幸好被旅馆保安发现，才把她救了出来。

根据上述材料，运用所学知识回答：