Single floating-point variable (+/-3.402823x10E+38 .. +/-1.401298x10E-45). If no key word is specified, a variable is defined as Single, unless a statement from DefBool to DefVar is used.
单精度的浮点变量（3.402823 x 10E38 到 1.401298 x 10E-45）如果不指定关键字，也未使用 DefBool、DefVar 等语句，则变量将被定义为单精度类型。