a÷b×$\frac{1}{b}$÷c×$\frac{1}{c}$÷d×$\frac{1}{d}$等于（　　）

神州新春，全球同乐。目前，春节文化不仅在华人圈内大放异彩，越来越多的外国人也开始加入其中，各国政要甚至争相给全球华人拜年。春节文化超越国界的影响力主要缘于（   ）

①春节文化具有丰富内涵和独特魅力   

②经济全球化促进了中外文化交流与融合

③中国综合国力和国际地位日益提升   

④中外文化差异让外国人对春节文化充满好奇

阅读下列短文，从每小题的三个选项中选出最佳选项。B
    Water comes from the sea, the rain and the tap. Animals, plants and human beings all need water. It is important for our daily (日常的）life. We use water to wash clothes and vegetables. We use water to cook food, make drinks, wash our face and so on. Firemen use water to put out fires. Fanners use water to grow crops. Water is useful. We mustn't waste (浪费）water. We must save water. Turn off the tap when you are brushing your teeth. Don't take a shower too long. Use the same water many times.

一位同学的自述：我不太会讲话，同学聊天时总插不上嘴，似乎大家都不喜欢我，我感觉自己特别失败……这位同学的主要问题在于（    ）

. He put it firmly that in no case _______ give in to others on such matters.