（1）写出下列化学符号表示的意义： 

语法填空

    ____ (locate) in a mountainous region of Chengde city, the Jinshanling Great Wall section is the ____ (good) preserved part of the Great Wall from the Ming Dynasty with many ____ (origin) features.

    Three towers are must-sees at the Jinshanling Great Wall. Each tower contains ____ own legend. The General Tower was named to commemorate Wu Guihua, a heroine who sacrificed herself to resist invasions ____ the north. The Black Tower and the Taochun Tower were named to commemorate two girls, Heigu and Taochun, ____ made great contributions to the construction of the Great Wall.

    If you go, you will find yourself experiencing ____ (total) different scenery in four seasons. In spring, apricot flowers decorate the Great Wall. In summer, the winding dragon-shaped Great Wall ____ (surround) by a sea of green plants. In autumn, the Great Wall turns into a colorful place and in winter, heavy snow covers the Great Wall, ____ (add) a sense of magnificence and solemnity.

    The annual Apricot Flower Festival kicks off at the beginning of April. If you have time, you should witness the true ____ (beautiful) of the China's landmark.

下列关于染色体的描述，错误的是（     ）

某校运动员分组训练，若每组7人，余3人；若每组8人，则缺5人；设运动员人数为x人，组数为y组，则列方程组为（　　）

一台洗衣机，原价3000元，现在降价 $\frac{2}{15}$ .现在售价____元.。