读东北区自然地理环境概况分布图，回答下列问题，

在人类历史的长河中，多元的政治文明异彩纷呈，影响至深．结合所学回答：

如图，是一个长为30 $m$ ，宽为20 $m$ 的长方形花园，现要在花园中修建等宽的小道，剩余的地方种植花草．如图所示，要使种植花草的面积为532 $m^2$ ，那么小道进出口的宽度应为____  $m$ ．

C

    My name is Lin Tao. I am a Chinese boy. Now I'm studying in America. There are many kinds of clubs here. When I first come here, I don't know anything about clubs. I'm a shy boy, so I can't speak English well. In my first year in America, I don't like to speak to others. In my second year I have to change (改变) myself by doing some new things. I realize that school is not just about getting good grades (成绩), it's also about being part of a club. One day, when I go to the Media Center with my classmate Jim, he tells me something about the club. It's interesting, so I join it. I am in many clubs now. It's good to be part of a club. These clubs help me to make new friends.