大自然简直就是一个神奇的魔术师，把地球表面的景观塑造的如此惟妙惟肖，令人观止．图为南斯拉夫的“猫咪”山．形成“猫咪”山惟妙惟肖形态的根本力量来源是（　　）

完形填空

    The summer vacation is the best time for students．They can go outdoors and have fun．They can go to big cities to  1，or go to the countryside to 2the beauty of nature(大自然)．

    Peter is an American middle school student and he loves 3  very much．He always travels in his country．

    This summer vacation he wants to do4．He is interested in Chinese history． 5he is flying to Beijing and Xi'an for the summer vacation．He is leaving on l2th July and 6 New York on the last day of the month．He plans 7 a fantastic vacation．During the 8，he is visiting places of interest and going shopping．At night，he is  9  to enjoy the night views．,He is sure he will have a  10 time．