statement must be the first line in the module, before the first SUB. Generally, only arrays need to be declared explicitly. All other variables are declared according to the type-declaration character, or - if omitted - as the default type
语句必须是模块中的第一行，位于第一个子程序之前。通常，只有数组需要显式声明。所有其他变量都按照类型声明字符进行声明，而如果省略了类型声明字符，则声明为默认类型